diff --git a/rust/crates/api/src/error.rs b/rust/crates/api/src/error.rs
index d4dc0daa..e8ec73a4 100644
--- a/rust/crates/api/src/error.rs
+++ b/rust/crates/api/src/error.rs
@@ -52,13 +52,19 @@ pub enum ApiError {
         body_snippet: String,
         source: serde_json::Error,
     },
-    /// A provider returned an error response.
-    ///
-    /// Boxed: the payload is ~139 bytes, and `ApiError` is the `Err` half of nearly every
-    /// `Result` in this crate, so inlining it inflates the size of every one of those returns
-    /// (clippy::result_large_err). Boxing keeps `ApiError` small and means adding a field here
-    /// cannot silently re-inflate every signature in the crate.
-    Api(Box<ApiErrorDetails>),
+    Api {
+        status: reqwest::StatusCode,
+        error_type: Option<String>,
+        message: Option<String>,
+        request_id: Option<String>,
+        body: String,
+        retryable: bool,
+        /// Suggested user action based on error type (e.g., "Reduce prompt size" for 413)
+        suggested_action: Option<String>,
+        /// Parsed Retry-After header value (seconds) for 429 responses.
+        /// When present, overrides the exponential backoff delay.
+        retry_after: Option<Duration>,
+    },
     RetriesExhausted {
         attempts: u32,
         last_error: Box<ApiError>,
@@ -75,38 +81,7 @@ pub enum ApiError {
     },
 }
 
-/// Payload of [`ApiError::Api`], held behind a `Box` so the enum stays small.
-#[derive(Debug)]
-pub struct ApiErrorDetails {
-    pub status: reqwest::StatusCode,
-    pub error_type: Option<String>,
-    pub message: Option<String>,
-    pub request_id: Option<String>,
-    pub body: String,
-    pub retryable: bool,
-    /// Suggested user action based on error type (e.g., "Reduce prompt size" for 413)
-    pub suggested_action: Option<String>,
-    /// Parsed Retry-After header value (seconds) for 429 responses.
-    /// When present, overrides the exponential backoff delay.
-    pub retry_after: Option<Duration>,
-}
-
 impl ApiError {
-    /// Convenience constructor so callers do not have to spell out the `Box` at every site.
-    #[must_use]
-    pub fn api(details: ApiErrorDetails) -> Self {
-        Self::Api(Box::new(details))
-    }
-
-    /// Borrow the provider-error payload, if this is one.
-    #[must_use]
-    pub fn api_details(&self) -> Option<&ApiErrorDetails> {
-        match self {
-            Self::Api(details) => Some(details),
-            _ => None,
-        }
-    }
-
     #[must_use]
     pub const fn missing_credentials(
         provider: &'static str,
@@ -162,7 +137,7 @@ impl ApiError {
     /// over the computed backoff delay when it exists.
     pub fn retry_after(&self) -> Option<Duration> {
         match self {
-            Self::Api(details) => details.retry_after,
+            Self::Api { retry_after, .. } => *retry_after,
             Self::RetriesExhausted { last_error, .. } => last_error.retry_after(),
             _ => None,
         }
@@ -171,7 +146,7 @@ impl ApiError {
     pub fn is_retryable(&self) -> bool {
         match self {
             Self::Http(error) => error.is_connect() || error.is_timeout() || error.is_request(),
-            Self::Api(details) => details.retryable,
+            Self::Api { retryable, .. } => *retryable,
             Self::RetriesExhausted { last_error, .. } => last_error.is_retryable(),
             Self::MissingCredentials { .. }
             | Self::ContextWindowExceeded { .. }
@@ -189,7 +164,7 @@ impl ApiError {
     #[must_use]
     pub fn request_id(&self) -> Option<&str> {
         match self {
-            Self::Api(details) => details.request_id.as_deref(),
+            Self::Api { request_id, .. } => request_id.as_deref(),
             Self::RetriesExhausted { last_error, .. } => last_error.request_id(),
             Self::MissingCredentials { .. }
             | Self::ContextWindowExceeded { .. }
@@ -216,12 +191,12 @@ impl ApiError {
             Self::MissingCredentials { .. } | Self::ExpiredOAuthToken | Self::Auth(_) => {
                 "provider_auth"
             }
-            Self::Api(details) if matches!(details.status.as_u16(), 401 | 403) => "provider_auth",
+            Self::Api { status, .. } if matches!(status.as_u16(), 401 | 403) => "provider_auth",
             Self::ContextWindowExceeded { .. } => "context_window",
-            Self::Api(_) if self.is_context_window_failure() => "context_window",
-            Self::Api(details) if details.status.as_u16() == 429 => "provider_rate_limit",
-            Self::Api(_) if self.is_generic_fatal_wrapper() => "provider_internal",
-            Self::Api(_) => "provider_error",
+            Self::Api { .. } if self.is_context_window_failure() => "context_window",
+            Self::Api { status, .. } if status.as_u16() == 429 => "provider_rate_limit",
+            Self::Api { .. } if self.is_generic_fatal_wrapper() => "provider_internal",
+            Self::Api { .. } => "provider_error",
             Self::Http(_) | Self::InvalidSseFrame(_) | Self::BackoffOverflow { .. } => {
                 "provider_transport"
             }
@@ -233,12 +208,11 @@ impl ApiError {
     #[must_use]
     pub fn is_generic_fatal_wrapper(&self) -> bool {
         match self {
-            Self::Api(details) => {
-                details
-                    .message
+            Self::Api { message, body, .. } => {
+                message
                     .as_deref()
                     .is_some_and(looks_like_generic_fatal_wrapper)
-                    || looks_like_generic_fatal_wrapper(&details.body)
+                    || looks_like_generic_fatal_wrapper(body)
             }
             Self::RetriesExhausted { last_error, .. } => last_error.is_generic_fatal_wrapper(),
             Self::MissingCredentials { .. }
@@ -255,36 +229,21 @@ impl ApiError {
         }
     }
 
-    /// True for failures whose own text cannot say what went wrong: transport, decode, and frame
-    /// errors.
-    ///
-    /// These matter because a server that answers an oversized request with a non-SSE HTTP 500
-    /// body lands here rather than in [`Self::is_context_window_failure`] — reqwest reports
-    /// "error decoding response body" and the real cause is lost. Callers that know how large the
-    /// request was can combine the two signals; callers that do not must treat this as unknown,
-    /// never as an overflow.
-    #[must_use]
-    pub fn is_ambiguous_transport_failure(&self) -> bool {
-        match self {
-            Self::Http(_) | Self::Json { .. } | Self::InvalidSseFrame(_) => true,
-            Self::RetriesExhausted { last_error, .. } => {
-                last_error.is_ambiguous_transport_failure()
-            }
-            _ => false,
-        }
-    }
-
     #[must_use]
     pub fn is_context_window_failure(&self) -> bool {
         match self {
             Self::ContextWindowExceeded { .. } => true,
-            Self::Api(details) => {
-                matches!(details.status.as_u16(), 400 | 413 | 422)
-                    && (details
-                        .message
+            Self::Api {
+                status,
+                message,
+                body,
+                ..
+            } => {
+                matches!(status.as_u16(), 400 | 413 | 422)
+                    && (message
                         .as_deref()
                         .is_some_and(looks_like_context_window_error)
-                        || looks_like_context_window_error(&details.body))
+                        || looks_like_context_window_error(body))
             }
             Self::RetriesExhausted { last_error, .. } => last_error.is_context_window_failure(),
             Self::MissingCredentials { .. }
@@ -368,14 +327,14 @@ impl Display for ApiError {
                 "failed to parse {provider} response for model {model}: {source}; first 200 chars of body: {body_snippet}"
             ),
             // #28: enhance 401/403 errors with actionable auth guidance
-            Self::Api(details) if matches!(details.status.as_u16(), 401 | 403) => {
-                let (status, error_type, message, request_id, body) = (
-                    &details.status,
-                    &details.error_type,
-                    &details.message,
-                    &details.request_id,
-                    &details.body,
-                );
+            Self::Api {
+                status,
+                error_type,
+                message,
+                request_id,
+                body,
+                ..
+            } if matches!(status.as_u16(), 401 | 403) => {
                 if let (Some(error_type), Some(message)) = (error_type, message) {
                     write!(f, "api returned {status} ({error_type})")?;
                     if let Some(request_id) = request_id {
@@ -397,14 +356,14 @@ impl Display for ApiError {
                      Run `claw doctor` to verify your credential configuration."
                 )
             }
-            Self::Api(details) => {
-                let (status, error_type, message, request_id, body) = (
-                    &details.status,
-                    &details.error_type,
-                    &details.message,
-                    &details.request_id,
-                    &details.body,
-                );
+            Self::Api {
+                status,
+                error_type,
+                message,
+                request_id,
+                body,
+                ..
+            } => {
                 if let (Some(error_type), Some(message)) = (error_type, message) {
                     write!(f, "api returned {status} ({error_type})")?;
                     if let Some(request_id) = request_id {
@@ -510,7 +469,6 @@ fn truncate_body_snippet(body: &str, max_chars: usize) -> String {
 
 #[cfg(test)]
 mod tests {
-    use super::ApiErrorDetails;
     use super::{truncate_body_snippet, ApiError};
 
     #[test]
@@ -575,7 +533,7 @@ mod tests {
 
     #[test]
     fn detects_generic_fatal_wrapper_and_classifies_it_as_provider_internal() {
-        let error = ApiError::Api(Box::new(ApiErrorDetails {
+        let error = ApiError::Api {
             status: reqwest::StatusCode::INTERNAL_SERVER_ERROR,
             error_type: Some("api_error".to_string()),
             message: Some(
@@ -587,7 +545,7 @@ mod tests {
             retryable: true,
             suggested_action: None,
         retry_after: None,
-        }));
+        };
 
         assert!(error.is_generic_fatal_wrapper());
         assert_eq!(error.safe_failure_class(), "provider_internal");
@@ -599,7 +557,7 @@ mod tests {
     fn retries_exhausted_preserves_nested_request_id_and_failure_class() {
         let error = ApiError::RetriesExhausted {
             attempts: 3,
-            last_error: Box::new(ApiError::Api(Box::new(ApiErrorDetails {
+            last_error: Box::new(ApiError::Api {
                 status: reqwest::StatusCode::BAD_GATEWAY,
                 error_type: Some("api_error".to_string()),
                 message: Some(
@@ -611,7 +569,7 @@ mod tests {
                 retryable: true,
                 suggested_action: None,
             retry_after: None,
-            }))),
+            }),
         };
 
         assert!(error.is_generic_fatal_wrapper());
@@ -621,7 +579,7 @@ mod tests {
 
     #[test]
     fn classifies_provider_context_window_errors() {
-        let error = ApiError::Api(Box::new(ApiErrorDetails {
+        let error = ApiError::Api {
             status: reqwest::StatusCode::BAD_REQUEST,
             error_type: Some("invalid_request_error".to_string()),
             message: Some(
@@ -633,7 +591,7 @@ mod tests {
             retryable: false,
             suggested_action: None,
         retry_after: None,
-        }));
+        };
 
         assert!(error.is_context_window_failure());
         assert_eq!(error.safe_failure_class(), "context_window");
@@ -642,7 +600,7 @@ mod tests {
 
     #[test]
     fn classifies_openai_configured_limit_errors_as_context_window_failures() {
-        let error = ApiError::Api(Box::new(ApiErrorDetails {
+        let error = ApiError::Api {
             status: reqwest::StatusCode::BAD_REQUEST,
             error_type: Some("invalid_request_error".to_string()),
             message: Some(
@@ -654,7 +612,7 @@ mod tests {
             retryable: false,
             suggested_action: None,
             retry_after: None,
-        }));
+        };
 
         assert!(error.is_context_window_failure());
         assert_eq!(error.safe_failure_class(), "context_window");
diff --git a/rust/crates/api/src/lib.rs b/rust/crates/api/src/lib.rs
index a4774f5a..e03d78ee 100644
--- a/rust/crates/api/src/lib.rs
+++ b/rust/crates/api/src/lib.rs
@@ -12,7 +12,7 @@ pub use client::{
     resolve_startup_auth_source, MessageStream, OAuthTokenSet, ProviderClient, ProviderConfig,
     ProviderConfigKind,
 };
-pub use error::{ApiError, ApiErrorDetails};
+pub use error::ApiError;
 pub use http_client::{
     build_http_client, build_http_client_or_default, build_http_client_with,
     build_http_client_with_opts, ProxyConfig, TimeoutConfig,
@@ -29,10 +29,9 @@ pub use providers::openai_compat::{
     OpenAiCompatClient, OpenAiCompatConfig,
 };
 pub use providers::{
-    context_window_override, detect_provider_kind, estimate_message_request_input_tokens,
-    max_tokens_for_model, max_tokens_for_model_with_override, model_family_identity_for,
-    model_family_identity_for_kind, model_token_limit, provider_diagnostics_for_model,
-    resolve_model_alias, ModelTokenLimit, ProviderDiagnostics, ProviderKind,
+    detect_provider_kind, max_tokens_for_model, max_tokens_for_model_with_override,
+    model_family_identity_for, model_family_identity_for_kind, provider_diagnostics_for_model,
+    resolve_model_alias, ProviderDiagnostics, ProviderKind,
 };
 pub use sse::{parse_frame, SseParser};
 pub use types::{
diff --git a/rust/crates/api/src/providers/anthropic.rs b/rust/crates/api/src/providers/anthropic.rs
index be6eb3a4..430b3eff 100644
--- a/rust/crates/api/src/providers/anthropic.rs
+++ b/rust/crates/api/src/providers/anthropic.rs
@@ -12,7 +12,7 @@ use serde::Deserialize;
 use serde_json::{Map, Value};
 use telemetry::{AnalyticsEvent, AnthropicRequestProfile, ClientIdentity, SessionTracer};
 
-use crate::error::{ApiError, ApiErrorDetails};
+use crate::error::ApiError;
 use crate::http_client::build_http_client_or_default;
 use crate::prompt_cache::{PromptCache, PromptCacheRecord, PromptCacheStats};
 
@@ -892,7 +892,7 @@ async fn expect_success(response: reqwest::Response) -> Result<reqwest::Response
     let retryable = is_retryable_status(status);
     let retry_after = parse_retry_after(&headers, status);
 
-    Err(ApiError::Api(Box::new(ApiErrorDetails {
+    Err(ApiError::Api {
         status,
         error_type: parsed_error
             .as_ref()
@@ -905,7 +905,7 @@ async fn expect_success(response: reqwest::Response) -> Result<reqwest::Response
         retryable,
         suggested_action: None,
         retry_after,
-    })))
+    })
 }
 
 fn parse_retry_after(
@@ -952,30 +952,86 @@ fn is_retryable_400(status: reqwest::StatusCode, body: &str) -> bool {
 const SK_ANT_BEARER_HINT: &str = "sk-ant-* keys go in ANTHROPIC_API_KEY (x-api-key header), not ANTHROPIC_AUTH_TOKEN (Bearer header). Move your key to ANTHROPIC_API_KEY.";
 
 fn enrich_bearer_auth_error(error: ApiError, auth: &AuthSource) -> ApiError {
-    let ApiError::Api(mut details) = error else {
+    let ApiError::Api {
+        status,
+        error_type,
+        message,
+        request_id,
+        body,
+        retryable,
+        suggested_action,
+        retry_after,
+        ..
+    } = error
+    else {
         return error;
     };
-    if details.status.as_u16() != 401 {
-        return ApiError::Api(details);
+    if status.as_u16() != 401 {
+        return ApiError::Api {
+            status,
+            error_type,
+            message,
+            request_id,
+            body,
+            retryable,
+            suggested_action,
+            retry_after,
+        };
     }
     let Some(bearer_token) = auth.bearer_token() else {
-        return ApiError::Api(details);
+        return ApiError::Api {
+            status,
+            error_type,
+            message,
+            request_id,
+            body,
+            retryable,
+            suggested_action,
+            retry_after,
+        };
     };
     if !bearer_token.starts_with("sk-ant-") {
-        return ApiError::Api(details);
+        return ApiError::Api {
+            status,
+            error_type,
+            message,
+            request_id,
+            body,
+            retryable,
+            suggested_action,
+            retry_after,
+        };
     }
     // Only append the hint when the AuthSource is pure BearerToken. If both
     // api_key and bearer_token are present (`ApiKeyAndBearer`), the x-api-key
     // header is already being sent alongside the Bearer header and the 401
     // is coming from a different cause — adding the hint would be misleading.
     if auth.api_key().is_some() {
-        return ApiError::Api(details);
+        return ApiError::Api {
+            status,
+            error_type,
+            message,
+            request_id,
+            body,
+            retryable,
+            suggested_action,
+            retry_after,
+        };
+    }
+    let enriched_message = match message {
+        Some(existing) => Some(format!("{existing} — hint: {SK_ANT_BEARER_HINT}")),
+        None => Some(format!("hint: {SK_ANT_BEARER_HINT}")),
+    };
+    ApiError::Api {
+        status,
+        error_type,
+        message: enriched_message,
+        request_id,
+        body,
+        retryable,
+        suggested_action,
+        retry_after,
     }
-    details.message = Some(match details.message.take() {
-        Some(existing) => format!("{existing} — hint: {SK_ANT_BEARER_HINT}"),
-        None => format!("hint: {SK_ANT_BEARER_HINT}"),
-    });
-    ApiError::Api(details)
 }
 
 fn anthropic_wire_model(model: &str) -> &str {
@@ -1027,7 +1083,6 @@ struct AnthropicErrorBody {
 #[cfg(test)]
 mod tests {
     use super::{ALT_REQUEST_ID_HEADER, REQUEST_ID_HEADER};
-    use crate::error::ApiErrorDetails;
     use std::io::{Read, Write};
     use std::net::TcpListener;
     use std::sync::{Mutex, OnceLock};
@@ -1592,7 +1647,7 @@ mod tests {
     fn enrich_bearer_auth_error_appends_sk_ant_hint_on_401_with_pure_bearer_token() {
         // given
         let auth = AuthSource::BearerToken("sk-ant-api03-deadbeef".to_string());
-        let error = crate::error::ApiError::Api(Box::new(ApiErrorDetails {
+        let error = crate::error::ApiError::Api {
             status: reqwest::StatusCode::UNAUTHORIZED,
             error_type: Some("authentication_error".to_string()),
             message: Some("Invalid bearer token".to_string()),
@@ -1601,7 +1656,7 @@ mod tests {
             retryable: false,
             suggested_action: None,
             retry_after: None,
-        }));
+        };
 
         // when
         let enriched = super::enrich_bearer_auth_error(error, &auth);
@@ -1623,8 +1678,8 @@ mod tests {
             "request id should still flow through the enriched error: {rendered}"
         );
         match enriched {
-            crate::error::ApiError::Api(details) => {
-                assert_eq!(details.status, reqwest::StatusCode::UNAUTHORIZED);
+            crate::error::ApiError::Api { status, .. } => {
+                assert_eq!(status, reqwest::StatusCode::UNAUTHORIZED);
             }
             other => panic!("expected Api variant, got {other:?}"),
         }
@@ -1634,7 +1689,7 @@ mod tests {
     fn enrich_bearer_auth_error_leaves_non_401_errors_unchanged() {
         // given
         let auth = AuthSource::BearerToken("sk-ant-api03-deadbeef".to_string());
-        let error = crate::error::ApiError::Api(Box::new(ApiErrorDetails {
+        let error = crate::error::ApiError::Api {
             status: reqwest::StatusCode::INTERNAL_SERVER_ERROR,
             error_type: Some("api_error".to_string()),
             message: Some("internal server error".to_string()),
@@ -1643,7 +1698,7 @@ mod tests {
             retryable: true,
             suggested_action: None,
             retry_after: None,
-        }));
+        };
 
         // when
         let enriched = super::enrich_bearer_auth_error(error, &auth);
@@ -1664,7 +1719,7 @@ mod tests {
     fn enrich_bearer_auth_error_ignores_401_when_bearer_token_is_not_sk_ant() {
         // given
         let auth = AuthSource::BearerToken("oauth-access-token-opaque".to_string());
-        let error = crate::error::ApiError::Api(Box::new(ApiErrorDetails {
+        let error = crate::error::ApiError::Api {
             status: reqwest::StatusCode::UNAUTHORIZED,
             error_type: Some("authentication_error".to_string()),
             message: Some("Invalid bearer token".to_string()),
@@ -1673,7 +1728,7 @@ mod tests {
             retryable: false,
             suggested_action: None,
             retry_after: None,
-        }));
+        };
 
         // when
         let enriched = super::enrich_bearer_auth_error(error, &auth);
@@ -1693,7 +1748,7 @@ mod tests {
             api_key: "sk-ant-api03-legitimate".to_string(),
             bearer_token: "sk-ant-api03-deadbeef".to_string(),
         };
-        let error = crate::error::ApiError::Api(Box::new(ApiErrorDetails {
+        let error = crate::error::ApiError::Api {
             status: reqwest::StatusCode::UNAUTHORIZED,
             error_type: Some("authentication_error".to_string()),
             message: Some("Invalid bearer token".to_string()),
@@ -1702,7 +1757,7 @@ mod tests {
             retryable: false,
             suggested_action: None,
             retry_after: None,
-        }));
+        };
 
         // when
         let enriched = super::enrich_bearer_auth_error(error, &auth);
@@ -1719,7 +1774,7 @@ mod tests {
     fn enrich_bearer_auth_error_ignores_401_when_auth_source_has_no_bearer() {
         // given
         let auth = AuthSource::ApiKey("sk-ant-api03-legitimate".to_string());
-        let error = crate::error::ApiError::Api(Box::new(ApiErrorDetails {
+        let error = crate::error::ApiError::Api {
             status: reqwest::StatusCode::UNAUTHORIZED,
             error_type: Some("authentication_error".to_string()),
             message: Some("Invalid x-api-key".to_string()),
@@ -1728,7 +1783,7 @@ mod tests {
             retryable: false,
             suggested_action: None,
             retry_after: None,
-        }));
+        };
 
         // when
         let enriched = super::enrich_bearer_auth_error(error, &auth);
diff --git a/rust/crates/api/src/providers/mod.rs b/rust/crates/api/src/providers/mod.rs
index 9c567a06..993a4e7d 100644
--- a/rust/crates/api/src/providers/mod.rs
+++ b/rust/crates/api/src/providers/mod.rs
@@ -619,43 +619,16 @@ fn web_passthrough_diagnostic(
     }
 }
 
-/// Overrides the context window every sizing guard is computed against.
-///
-/// The model *name* is not a reliable statement of the window when the endpoint is a local
-/// server: the harness sends its compiled-in default name (a Claude alias) while the backend
-/// serves whatever `-c` it was started with. Every guard downstream of [`model_token_limit`]
-/// then sizes itself against the name's window instead of the real one, which makes the
-/// preflights unable to fire rather than merely inaccurate. This variable is the operator's
-/// statement of the truth, and it wins over the table.
-const CONTEXT_WINDOW_ENV_VAR: &str = "CLAW_CONTEXT_WINDOW";
-
-/// Fraction of the window a single response may be allowed to claim when the window is
-/// declared. Output and input share one budget on a local server, so reserving a quarter for
-/// the reply leaves three quarters for prompt plus transcript.
-const MAX_OUTPUT_SHARE_OF_WINDOW: u32 = 4;
-
-/// The operator-declared context window, when set and parseable as a positive token count.
-#[must_use]
-pub fn context_window_override() -> Option<u32> {
-    parse_context_window_override(std::env::var(CONTEXT_WINDOW_ENV_VAR).ok().as_deref())
-}
-
-#[must_use]
-fn parse_context_window_override(value: Option<&str>) -> Option<u32> {
-    value
-        .and_then(|raw| raw.trim().parse::<u32>().ok())
-        .filter(|window| *window > 0)
-}
-
 #[must_use]
 pub fn max_tokens_for_model(model: &str) -> u32 {
-    // A declared window caps the reply too. Asking a 65k server for 32k of output reserves half
-    // the window for a single message, which the server then silently clamps — leaving the
-    // client's own accounting wrong by the difference.
-    model_token_limit(model).map_or_else(
-        || max_tokens_for_model_by_name(model),
-        |limit| max_tokens_for_model_by_name(model).min(limit.max_output_tokens),
-    )
+    let canonical = resolve_model_alias(model);
+    let heuristic = if canonical.contains("opus") {
+        32_000
+    } else {
+        64_000
+    };
+
+    model_token_limit(model).map_or(heuristic, |limit| heuristic.min(limit.max_output_tokens))
 }
 
 /// Returns the effective max output tokens for a model, preferring a plugin
@@ -668,33 +641,6 @@ pub fn max_tokens_for_model_with_override(model: &str, plugin_override: Option<u
 
 #[must_use]
 pub fn model_token_limit(model: &str) -> Option<ModelTokenLimit> {
-    // A declared window replaces the table's, and supplies one for models the table has never
-    // heard of. Returning `Some` for an unknown model is the point: `None` makes both preflights
-    // return `Ok` without looking at anything, so an unrecognised local model gets no guard at all.
-    if let Some(context_window_tokens) = context_window_override() {
-        return Some(ModelTokenLimit {
-            max_output_tokens: max_tokens_for_model_by_name(model)
-                .min(context_window_tokens / MAX_OUTPUT_SHARE_OF_WINDOW),
-            context_window_tokens,
-        });
-    }
-    model_token_limit_by_name(model)
-}
-
-#[must_use]
-fn max_tokens_for_model_by_name(model: &str) -> u32 {
-    let canonical = resolve_model_alias(model);
-    let heuristic = if canonical.contains("opus") {
-        32_000
-    } else {
-        64_000
-    };
-    model_token_limit_by_name(model)
-        .map_or(heuristic, |limit| heuristic.min(limit.max_output_tokens))
-}
-
-#[must_use]
-fn model_token_limit_by_name(model: &str) -> Option<ModelTokenLimit> {
     let canonical = resolve_model_alias(model);
     let base_model = canonical.rsplit('/').next().unwrap_or(canonical.as_str());
     match base_model {
@@ -777,7 +723,7 @@ pub fn preflight_message_request(request: &MessageRequest) -> Result<(), ApiErro
     Ok(())
 }
 
-pub fn estimate_message_request_input_tokens(request: &MessageRequest) -> u32 {
+fn estimate_message_request_input_tokens(request: &MessageRequest) -> u32 {
     let mut estimate = estimate_serialized_tokens(&request.messages);
     estimate = estimate.saturating_add(estimate_serialized_tokens(&request.system));
     estimate = estimate.saturating_add(estimate_serialized_tokens(&request.tools));
diff --git a/rust/crates/api/src/providers/openai_compat.rs b/rust/crates/api/src/providers/openai_compat.rs
index 183bd35d..e1cca048 100644
--- a/rust/crates/api/src/providers/openai_compat.rs
+++ b/rust/crates/api/src/providers/openai_compat.rs
@@ -7,7 +7,7 @@ use std::time::{Duration, SystemTime, UNIX_EPOCH};
 use serde::Deserialize;
 use serde_json::{json, Value};
 
-use crate::error::{ApiError, ApiErrorDetails};
+use crate::error::ApiError;
 use crate::http_client::build_http_client_or_default;
 use crate::types::{
     ContentBlockDelta, ContentBlockDeltaEvent, ContentBlockStartEvent, ContentBlockStopEvent,
@@ -239,7 +239,7 @@ impl OpenAiCompatClient {
                     .get("code")
                     .and_then(serde_json::Value::as_u64)
                     .map(|c| c as u16);
-                return Err(ApiError::Api(Box::new(ApiErrorDetails {
+                return Err(ApiError::Api {
                     status: reqwest::StatusCode::from_u16(code.unwrap_or(400))
                         .unwrap_or(reqwest::StatusCode::BAD_REQUEST),
                     error_type: err_obj
@@ -255,7 +255,7 @@ impl OpenAiCompatClient {
                             .unwrap_or(reqwest::StatusCode::BAD_REQUEST),
                     ),
                     retry_after: None,
-                })));
+                });
             }
         }
         let payload = serde_json::from_str::<ChatCompletionResponse>(&body).map_err(|error| {
@@ -1613,7 +1613,7 @@ fn parse_sse_frame(
                     .map(|c| c as u16);
                 let status = reqwest::StatusCode::from_u16(code.unwrap_or(500))
                     .unwrap_or(reqwest::StatusCode::INTERNAL_SERVER_ERROR);
-                return Err(ApiError::Api(Box::new(ApiErrorDetails {
+                return Err(ApiError::Api {
                     status,
                     error_type: err_obj
                         .get("type")
@@ -1625,12 +1625,12 @@ fn parse_sse_frame(
                     retryable: false,
                     suggested_action: suggested_action_for_status(status),
                     retry_after: None,
-                })));
+                });
             }
         }
         // Detect HTML responses
         if trimmed.starts_with('<') || trimmed.starts_with("<!") {
-            return Err(ApiError::Api(Box::new(ApiErrorDetails {
+            return Err(ApiError::Api {
                 status: reqwest::StatusCode::BAD_REQUEST,
                 error_type: Some("invalid_response".to_string()),
                 message: Some(
@@ -1641,7 +1641,7 @@ fn parse_sse_frame(
                 retryable: false,
                 suggested_action: Some("verify the API endpoint URL is correct".to_string()),
                 retry_after: None,
-            })));
+            });
         }
         return Ok(None);
     }
@@ -1665,7 +1665,7 @@ fn parse_sse_frame(
                 .map(|c| c as u16);
             let status = reqwest::StatusCode::from_u16(code.unwrap_or(400))
                 .unwrap_or(reqwest::StatusCode::BAD_REQUEST);
-            return Err(ApiError::Api(Box::new(ApiErrorDetails {
+            return Err(ApiError::Api {
                 status,
                 error_type: err_obj
                     .get("type")
@@ -1677,13 +1677,13 @@ fn parse_sse_frame(
                 retryable: false,
                 suggested_action: suggested_action_for_status(status),
                 retry_after: None,
-            })));
+            });
         }
     }
     // Detect HTML or other non-JSON responses early for better error messages
     let trimmed_payload = payload.trim();
     if trimmed_payload.starts_with('<') || trimmed_payload.starts_with("<!") {
-        return Err(ApiError::Api(Box::new(ApiErrorDetails {
+        return Err(ApiError::Api {
             status: reqwest::StatusCode::BAD_REQUEST,
             error_type: Some("invalid_response".to_string()),
             message: Some(
@@ -1694,7 +1694,7 @@ fn parse_sse_frame(
             retryable: false,
             suggested_action: Some("verify the API endpoint URL is correct".to_string()),
             retry_after: None,
-        })));
+        });
     }
     serde_json::from_str::<ChatCompletionChunk>(&payload)
         .map(Some)
@@ -1754,7 +1754,7 @@ async fn expect_success(response: reqwest::Response) -> Result<reqwest::Response
 
     let suggested_action = suggested_action_for_status(status);
 
-    Err(ApiError::Api(Box::new(ApiErrorDetails {
+    Err(ApiError::Api {
         status,
         error_type: parsed_error
             .as_ref()
@@ -1767,7 +1767,7 @@ async fn expect_success(response: reqwest::Response) -> Result<reqwest::Response
         retryable,
         suggested_action,
         retry_after,
-    })))
+    })
 }
 
 fn parse_retry_after(
diff --git a/rust/crates/api/tests/client_integration.rs b/rust/crates/api/tests/client_integration.rs
index 82501c28..c53e34c5 100644
--- a/rust/crates/api/tests/client_integration.rs
+++ b/rust/crates/api/tests/client_integration.rs
@@ -585,11 +585,14 @@ async fn surfaces_retry_exhaustion_for_persistent_retryable_errors() {
             last_error,
         } => {
             assert_eq!(attempts, 2);
-            let details = last_error
-                .api_details()
-                .expect("last error should be a provider Api error");
-            assert_eq!(details.status, reqwest::StatusCode::SERVICE_UNAVAILABLE);
-            assert!(details.retryable);
+            assert!(matches!(
+                *last_error,
+                ApiError::Api {
+                    status: reqwest::StatusCode::SERVICE_UNAVAILABLE,
+                    retryable: true,
+                    ..
+                }
+            ));
         }
         other => panic!("expected retries exhausted, got {other:?}"),
     }
diff --git a/rust/crates/claw-rag-service/src/ingest.rs b/rust/crates/claw-rag-service/src/ingest.rs
index c7083d14..eae43629 100644
--- a/rust/crates/claw-rag-service/src/ingest.rs
+++ b/rust/crates/claw-rag-service/src/ingest.rs
@@ -66,7 +66,7 @@ async fn flush_path_batch(
     #[cfg(feature = "qdrant-index")]
     let mut qdrant_points: Vec<ChunkPoint> = Vec::with_capacity(batch.len());
 
-    for ((ord, t), vec) in batch.drain(..).zip(vecs) {
+    for ((ord, t), vec) in batch.drain(..).zip(vecs.into_iter()) {
         let dim = vec.len();
         let cid = insert_chunk(conn, path, ord, &t)?;
         insert_embedding(conn, cid, dim, &vec)?;
diff --git a/rust/crates/runtime/src/compact.rs b/rust/crates/runtime/src/compact.rs
index d0273f44..797d3a6b 100644
--- a/rust/crates/runtime/src/compact.rs
+++ b/rust/crates/runtime/src/compact.rs
@@ -95,21 +95,10 @@ pub fn get_compact_continuation_message(
 #[must_use]
 pub fn compact_session(session: &Session, config: CompactionConfig) -> CompactionResult {
     if !should_compact(session, config) {
-        // "Nothing to drop" is not the same as "nothing to do". A session can exceed the window
-        // while holding fewer messages than `preserve_recent_messages` — a single read of a large
-        // file does it — and message-granular compaction has no move to make there. Trim the
-        // payloads anyway, so the one lever that still works is not gated behind the one that
-        // does not.
-        let mut trimmed_session = session.clone();
-        trimmed_session.messages = session
-            .messages
-            .iter()
-            .map(truncate_oversized_tool_results)
-            .collect();
         return CompactionResult {
             summary: String::new(),
             formatted_summary: String::new(),
-            compacted_session: trimmed_session,
+            compacted_session: session.clone(),
             removed_message_count: 0,
         };
     }
@@ -176,14 +165,7 @@ pub fn compact_session(session: &Session, config: CompactionConfig) -> Compactio
         k
     };
     let removed = &session.messages[compacted_prefix_len..keep_from];
-    // Dropping whole messages is not enough on its own. An agentic turn is five messages
-    // (user / assistant+tool_use / tool_result / assistant+tool_use / tool_result), so the
-    // preserved tail IS the pair of tool results that overflowed the window, and the only
-    // message compaction may drop is the short user prompt. Trim the payloads that must stay.
-    let preserved = session.messages[keep_from..]
-        .iter()
-        .map(truncate_oversized_tool_results)
-        .collect::<Vec<_>>();
+    let preserved = session.messages[keep_from..].to_vec();
     let summary =
         merge_compact_summaries(existing_summary.as_deref(), &summarize_messages(removed));
     let formatted_summary = format_compact_summary(&summary);
@@ -208,78 +190,6 @@ pub fn compact_session(session: &Session, config: CompactionConfig) -> Compactio
     }
 }
 
-/// Largest tool-result payload compaction will preserve verbatim, in characters.
-///
-/// ~16 KB is ~4 k tokens: big enough that ordinary tool output is never touched, small enough
-/// that several preserved results still fit a small window.
-const MAX_PRESERVED_TOOL_RESULT_CHARS: usize = 16 * 1024;
-
-/// Characters kept from the tail of a trimmed payload. The head carries the structure a model
-/// needs to recognise what it read; the tail is where a file's most recent edits usually are.
-const PRESERVED_TOOL_RESULT_TAIL_CHARS: usize = 2 * 1024;
-
-/// Returns `message` with any oversized `ToolResult` payload replaced by a head/tail excerpt.
-///
-/// Clones only when something is actually trimmed, so the common path stays cheap.
-fn truncate_oversized_tool_results(message: &ConversationMessage) -> ConversationMessage {
-    let needs_trim = message.blocks.iter().any(|block| match block {
-        ContentBlock::ToolResult { output, .. } => {
-            output.chars().count() > MAX_PRESERVED_TOOL_RESULT_CHARS
-        }
-        _ => false,
-    });
-    if !needs_trim {
-        return message.clone();
-    }
-
-    let blocks = message
-        .blocks
-        .iter()
-        .map(|block| match block {
-            ContentBlock::ToolResult {
-                tool_use_id,
-                tool_name,
-                output,
-                is_error,
-            } => ContentBlock::ToolResult {
-                tool_use_id: tool_use_id.clone(),
-                tool_name: tool_name.clone(),
-                output: excerpt_tool_result(output),
-                is_error: *is_error,
-            },
-            other => other.clone(),
-        })
-        .collect();
-
-    ConversationMessage {
-        role: message.role,
-        blocks,
-        usage: message.usage,
-    }
-}
-
-/// Builds a head + marker + tail excerpt of an oversized tool-result payload.
-///
-/// Operates on chars, not bytes, so a multi-byte boundary can never be split.
-fn excerpt_tool_result(output: &str) -> String {
-    let chars: Vec<char> = output.chars().collect();
-    let total = chars.len();
-    if total <= MAX_PRESERVED_TOOL_RESULT_CHARS {
-        return output.to_string();
-    }
-
-    let tail_len = PRESERVED_TOOL_RESULT_TAIL_CHARS.min(total);
-    let head_len = MAX_PRESERVED_TOOL_RESULT_CHARS.saturating_sub(tail_len);
-    let elided = total.saturating_sub(head_len + tail_len);
-    if elided == 0 {
-        return output.to_string();
-    }
-
-    let head: String = chars[..head_len].iter().collect();
-    let tail: String = chars[total - tail_len..].iter().collect();
-    format!("{head}\n\n[... {elided} characters elided by compaction; re-read this file if you need the omitted portion ...]\n\n{tail}")
-}
-
 fn compacted_summary_prefix_len(session: &Session) -> usize {
     usize::from(
         session
@@ -663,7 +573,7 @@ fn extract_summary_timeline(summary: &str) -> Vec<String> {
 #[cfg(test)]
 mod tests {
     use super::{
-        collect_key_files, compact_session, estimate_session_tokens, format_compact_summary,
+        collect_key_files, compact_session, format_compact_summary,
         get_compact_continuation_message, infer_pending_work, should_compact, CompactionConfig,
     };
     use crate::session::{ContentBlock, ConversationMessage, MessageRole, Session};
@@ -853,185 +763,6 @@ mod tests {
     /// user(ToolResult) pair at the boundary. An orphaned tool-result message
     /// without the preceding assistant `tool_calls` causes a 400 on the
     /// OpenAI-compat path (gaebal-gajae repro 2026-04-09).
-    /// The failure this exists for: an agentic turn is 5 messages (user / assistant+tool_use /
-    /// tool_result / assistant+tool_use / tool_result), so `preserve_recent_messages: 4` protects
-    /// exactly the two giant tool results that overflow the window. Message-granular compaction
-    /// can only drop the tiny user prompt, so the payloads themselves must be trimmed.
-    #[test]
-    fn compaction_truncates_oversized_tool_results_it_must_preserve() {
-        let huge = "z".repeat(80_000);
-        let mut session = Session::new();
-        session
-            .push_message(ConversationMessage::user_text("read two files"))
-            .expect("user message");
-        session
-            .push_message(ConversationMessage::assistant(vec![
-                ContentBlock::ToolUse {
-                    id: "call-1".to_string(),
-                    name: "read_file".to_string(),
-                    input: "{\"path\":\"a.rs\"}".to_string(),
-                },
-            ]))
-            .expect("assistant tool use");
-        session
-            .push_message(ConversationMessage::tool_result(
-                "call-1",
-                "read_file",
-                huge.clone(),
-                false,
-            ))
-            .expect("tool result");
-        session
-            .push_message(ConversationMessage::assistant(vec![
-                ContentBlock::ToolUse {
-                    id: "call-2".to_string(),
-                    name: "read_file".to_string(),
-                    input: "{\"path\":\"b.rs\"}".to_string(),
-                },
-            ]))
-            .expect("second assistant tool use");
-        session
-            .push_message(ConversationMessage::tool_result(
-                "call-2",
-                "read_file",
-                huge.clone(),
-                false,
-            ))
-            .expect("second tool result");
-
-        let before = estimate_session_tokens(&session);
-        let result = compact_session(
-            &session,
-            CompactionConfig {
-                preserve_recent_messages: 4,
-                max_estimated_tokens: 0,
-            },
-        );
-        let after = estimate_session_tokens(&result.compacted_session);
-
-        assert!(
-            after < before / 2,
-            "compaction must shrink an oversized preserved tool result: {before} -> {after}"
-        );
-
-        let preserved_output = result
-            .compacted_session
-            .messages
-            .iter()
-            .flat_map(|message| &message.blocks)
-            .find_map(|block| match block {
-                ContentBlock::ToolResult { output, .. } => Some(output.clone()),
-                _ => None,
-            })
-            .expect("the tool result must still be present, not deleted");
-
-        assert!(
-            preserved_output.len() < huge.len(),
-            "the payload must actually be trimmed"
-        );
-        assert!(
-            preserved_output.contains("elided"),
-            "the model must be told the view is partial, got: {}",
-            &preserved_output[..preserved_output.len().min(200)]
-        );
-        assert!(
-            preserved_output.starts_with('z'),
-            "the head of the output must be kept"
-        );
-        assert!(
-            preserved_output.ends_with('z'),
-            "the tail of the output must be kept"
-        );
-    }
-
-    /// A session can exceed the window while holding FEWER messages than
-    /// `preserve_recent_messages` — one read of a large file does it. `should_compact` returns
-    /// false there (nothing is droppable), so trimming must not be gated behind it.
-    #[test]
-    fn oversized_tool_results_are_trimmed_even_when_no_message_can_be_dropped() {
-        let huge = "q".repeat(80_000);
-        let mut session = Session::new();
-        session
-            .push_message(ConversationMessage::user_text("read one enormous file"))
-            .expect("user message");
-        session
-            .push_message(ConversationMessage::assistant(vec![
-                ContentBlock::ToolUse {
-                    id: "call-1".to_string(),
-                    name: "read_file".to_string(),
-                    input: "{\"path\":\"huge.rs\"}".to_string(),
-                },
-            ]))
-            .expect("assistant tool use");
-        session
-            .push_message(ConversationMessage::tool_result(
-                "call-1",
-                "read_file",
-                huge,
-                false,
-            ))
-            .expect("tool result");
-
-        // 3 messages, preserve 4: there is nothing to remove, yet the session is far too big.
-        let before = estimate_session_tokens(&session);
-        let result = compact_session(
-            &session,
-            CompactionConfig {
-                preserve_recent_messages: 4,
-                max_estimated_tokens: 0,
-            },
-        );
-        let after = estimate_session_tokens(&result.compacted_session);
-
-        assert!(
-            after < before / 2,
-            "an untrimmable session must still have its payloads trimmed: {before} -> {after}"
-        );
-    }
-
-    /// Trimming must not touch payloads that already fit — otherwise every ordinary tool result
-    /// would grow an elision marker it does not need.
-    #[test]
-    fn compaction_leaves_small_tool_results_untouched() {
-        let small = "ok".repeat(50);
-        let mut session = Session::new();
-        for index in 0..6 {
-            session
-                .push_message(ConversationMessage::user_text(format!("turn {index}")))
-                .expect("user message");
-            session
-                .push_message(ConversationMessage::tool_result(
-                    format!("call-{index}"),
-                    "read_file",
-                    small.clone(),
-                    false,
-                ))
-                .expect("tool result");
-        }
-
-        let result = compact_session(
-            &session,
-            CompactionConfig {
-                preserve_recent_messages: 4,
-                max_estimated_tokens: 0,
-            },
-        );
-
-        for block in result
-            .compacted_session
-            .messages
-            .iter()
-            .flat_map(|message| &message.blocks)
-        {
-            if let ContentBlock::ToolResult { output, .. } = block {
-                assert_eq!(
-                    output, &small,
-                    "a small tool result must pass through as-is"
-                );
-            }
-        }
-    }
-
     #[test]
     fn compaction_does_not_split_tool_use_tool_result_pair() {
         use crate::session::{ContentBlock, Session};
diff --git a/rust/crates/runtime/src/conversation.rs b/rust/crates/runtime/src/conversation.rs
index 851149b9..5a0ebc72 100644
--- a/rust/crates/runtime/src/conversation.rs
+++ b/rust/crates/runtime/src/conversation.rs
@@ -18,47 +18,6 @@ use crate::usage::{TokenUsage, UsageTracker};
 const DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD: u32 = 100_000;
 const AUTO_COMPACTION_THRESHOLD_ENV_VAR: &str = "CLAUDE_CODE_AUTO_COMPACT_INPUT_TOKENS";
 
-const DEFAULT_MAX_STALL_NUDGES: usize = 3;
-const MAX_STALL_NUDGES_ENV_VAR: &str = "CLAW_MAX_STALL_NUDGES";
-/// Placeholder recorded in the trace when a turn is resumed rather than started, so the trace
-/// does not attribute a second user message to a turn that only had one.
-const RESUMED_TURN_MARKER: &str = "[resumed turn]";
-/// Operator-declared context window. Kept as a literal rather than imported because `runtime`
-/// sits below `api` in the dependency graph; `api::context_window_override` reads the same name.
-const CONTEXT_WINDOW_ENV_VAR: &str = "CLAW_CONTEXT_WINDOW";
-/// Share of a declared context window at which compaction is triggered, leaving the remainder
-/// as headroom for the reply plus whatever the next tool result carries.
-const AUTO_COMPACTION_WINDOW_PERCENT: u32 = 70;
-
-/// Injected when the model narrates its next step (or asks for a go-ahead mid-task)
-/// instead of emitting the tool call that would perform it.
-const STALL_NUDGE_PROMPT: &str = "[auto-continue] You ended the turn without calling a tool, \
-     but the work is not finished. Do not describe the next step and do not ask for \
-     confirmation — issue the tool call now and keep going until the task is done. If \
-     everything asked for is genuinely complete, reply with a one-line summary containing \
-     no forward-looking sentence.";
-
-/// Phrases that mark text as an announcement of work the model has not performed yet.
-/// Matched against the final non-empty line of the assistant's reply.
-const PENDING_ACTION_MARKERS: [&str; 16] = [
-    "let me ",
-    "let's ",
-    "lets ",
-    "i'll ",
-    "i will ",
-    "i'm going to",
-    "i am going to",
-    "going to run",
-    "about to ",
-    "now running",
-    "now checking",
-    "now i",
-    "next i",
-    "next, i",
-    "proceeding to",
-    "moving on to",
-];
-
 /// Fully assembled request payload sent to the upstream model client.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ApiRequest {
@@ -131,7 +90,6 @@ impl std::error::Error for ToolError {}
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct RuntimeError {
     message: String,
-    context_window: bool,
 }
 
 impl RuntimeError {
@@ -139,28 +97,8 @@ impl RuntimeError {
     pub fn new(message: impl Into<String>) -> Self {
         Self {
             message: message.into(),
-            context_window: false,
         }
     }
-
-    /// A failure the caller may be able to clear by shrinking the session.
-    ///
-    /// This is a decision the API layer makes and hands up, not one the caller reconstructs by
-    /// matching substrings against the rendered message. Recovering from context exhaustion means
-    /// discarding conversation history, so a transport hiccup misread as an overflow destroys the
-    /// session for no reason — the classification has to come from whoever saw the real error.
-    #[must_use]
-    pub fn context_window(message: impl Into<String>) -> Self {
-        Self {
-            message: message.into(),
-            context_window: true,
-        }
-    }
-
-    #[must_use]
-    pub const fn is_context_window_failure(&self) -> bool {
-        self.context_window
-    }
 }
 
 impl Display for RuntimeError {
@@ -202,7 +140,6 @@ pub struct ConversationRuntime<C, T> {
     hook_abort_signal: HookAbortSignal,
     hook_progress_reporter: Option<Box<dyn HookProgressReporter>>,
     session_tracer: Option<SessionTracer>,
-    max_stall_nudges: usize,
 }
 
 impl<C, T> ConversationRuntime<C, T>
@@ -257,17 +194,9 @@ where
             hook_abort_signal: HookAbortSignal::default(),
             hook_progress_reporter: None,
             session_tracer: None,
-            max_stall_nudges: max_stall_nudges_from_env(),
         }
     }
 
-    /// Override how many auto-continue nudges a stalled turn may receive. `0` disables them.
-    #[must_use]
-    pub fn with_max_stall_nudges(mut self, max_stall_nudges: usize) -> Self {
-        self.max_stall_nudges = max_stall_nudges;
-        self
-    }
-
     #[must_use]
     pub fn with_max_iterations(mut self, max_iterations: usize) -> Self {
         self.max_iterations = max_iterations;
@@ -397,33 +326,14 @@ where
         }
     }
 
+    #[allow(clippy::too_many_lines)]
     pub fn run_turn(
         &mut self,
         user_input: impl Into<String>,
-        prompter: Option<&mut dyn PermissionPrompter>,
-    ) -> Result<TurnSummary, RuntimeError> {
-        self.drive_turn(Some(user_input.into()), prompter)
-    }
-
-    /// Continues the turn already recorded in the session, without adding a user message.
-    ///
-    /// Recovery paths retry a turn that failed part-way through. Calling [`Self::run_turn`] again
-    /// with the original input would append that input a second time and invite the model to redo
-    /// tool calls whose side effects have already landed. Resuming reads the transcript as it
-    /// stands — including the tool results that did complete — and carries on from there.
-    pub fn resume_turn(
-        &mut self,
-        prompter: Option<&mut dyn PermissionPrompter>,
-    ) -> Result<TurnSummary, RuntimeError> {
-        self.drive_turn(None, prompter)
-    }
-
-    #[allow(clippy::too_many_lines)]
-    fn drive_turn(
-        &mut self,
-        user_input: Option<String>,
         mut prompter: Option<&mut dyn PermissionPrompter>,
     ) -> Result<TurnSummary, RuntimeError> {
+        let user_input = user_input.into();
+
         // ROADMAP #38: Session-health canary - probe if context was compacted
         if self.session.compaction.is_some() {
             if let Err(error) = self.run_session_health_probe() {
@@ -435,24 +345,16 @@ where
             }
         }
 
-        match user_input {
-            Some(user_input) => {
-                self.record_turn_started(&user_input);
-                self.session
-                    .push_user_text(user_input)
-                    .map_err(|error| RuntimeError::new(error.to_string()))?;
-            }
-            None => self.record_turn_started(RESUMED_TURN_MARKER),
-        }
+        self.record_turn_started(&user_input);
+        self.session
+            .push_user_text(user_input)
+            .map_err(|error| RuntimeError::new(error.to_string()))?;
 
         let mut assistant_messages = Vec::new();
         let mut tool_results = Vec::new();
         let mut prompt_cache_events = Vec::new();
         let mut iterations = 0;
         let mut auto_compaction = None;
-        let max_stall_nudges = self.max_stall_nudges;
-        let mut stall_nudges = 0;
-        let mut tools_ran = false;
 
         loop {
             iterations += 1;
@@ -464,23 +366,6 @@ where
                 return Err(error);
             }
 
-            // Compact BEFORE the request goes out, not only after a reply lands.
-            //
-            // The usage-based check below is post-hoc: it can only see the context once a call
-            // has returned and reported its counters. Between that measurement and the next
-            // request the session can grow enormously — a reasoning model emitting a long
-            // <think> block, then a tool result carrying a large file. Observed live: a call
-            // measured at 17,858 prompt tokens generated 10,842 more, a read_file added ~19k on
-            // top, and the next request hit the provider at 47,755 tokens and was rejected
-            // outright. No amount of tuning the post-hoc threshold prevents that, because
-            // nothing measures the session in between.
-            //
-            // `estimate_session_tokens` is a local heuristic over the transcript, so this costs
-            // no API call and works before any usage has ever been recorded.
-            if let Some(compaction) = self.maybe_auto_compact_before_request() {
-                auto_compaction = Some(compaction);
-            }
-
             let request = ApiRequest {
                 system_prompt: self.system_prompt.clone(),
                 messages: self.session.messages.clone(),
@@ -496,7 +381,6 @@ where
                 match build_assistant_message(events) {
                     Ok(result) => result,
                     Err(error) => {
-                        let error = self.classify_empty_reply(error);
                         self.record_turn_failed(iterations, &error);
                         return Err(error);
                     }
@@ -533,35 +417,8 @@ where
             }
 
             if pending_tool_uses.is_empty() {
-                // A reply with no tool call usually means the turn is done. On small local
-                // models it just as often means the model narrated the next step — or asked
-                // for a go-ahead mid-task — and then emitted EOS, leaving the announced work
-                // undone. Nudge it back into the loop instead of dropping the user at the
-                // prompt, bounded so a model that insists it is finished still gets to stop.
-                let stalled = stall_nudges < max_stall_nudges
-                    && is_stalled_reply(
-                        &assistant_text(
-                            assistant_messages
-                                .last()
-                                .expect("assistant message pushed above"),
-                        ),
-                        tools_ran,
-                    );
-                if stalled {
-                    stall_nudges += 1;
-                    // Pushed as a system turn, not a user one. The model needs to see it, but the
-                    // transcript must not claim the user asked for it: this text is persisted,
-                    // re-sent on every later request, and folded into the next compaction summary,
-                    // where a user-labelled nudge becomes indistinguishable from something the
-                    // user actually said.
-                    self.session
-                        .push_message(ConversationMessage::system_text(STALL_NUDGE_PROMPT))
-                        .map_err(|error| RuntimeError::new(error.to_string()))?;
-                    continue;
-                }
                 break;
             }
-            tools_ran = true;
 
             for (tool_use_id, tool_name, input) in pending_tool_uses {
                 let pre_hook_result = self.run_pre_tool_use_hook(&tool_name, &input);
@@ -716,62 +573,13 @@ where
         self.session
     }
 
-    /// Compaction check run immediately before a request is sent, based on a locally estimated
-    /// transcript size rather than on provider-reported usage.
-    ///
-    /// This is the guard that actually keeps a session inside the context window: it sees growth
-    /// that usage counters cannot, because it runs after tool results and long generations have
-    /// been appended but before the request that would carry them is built.
-    /// Decides whether an empty or unreadable reply was an overflow, by size rather than by text.
-    ///
-    /// A stream that produces no content says nothing about why. Some backends answer an
-    /// oversized request that way instead of with a typed error, so the failure is worth
-    /// recovering from — but only when the session was already large enough for that to be the
-    /// plausible cause. Below the compaction threshold it is a blip, and discarding the
-    /// transcript would cost more than the retry could win.
-    fn classify_empty_reply(&self, error: RuntimeError) -> RuntimeError {
-        if error.is_context_window_failure() {
-            return error;
-        }
-        if estimate_session_tokens(&self.session)
-            >= self.auto_compaction_input_tokens_threshold as usize
-        {
-            return RuntimeError::context_window(error.to_string());
-        }
-        error
-    }
-
-    fn maybe_auto_compact_before_request(&mut self) -> Option<AutoCompactionEvent> {
-        let estimated = estimate_session_tokens(&self.session);
-        if estimated < self.auto_compaction_input_tokens_threshold as usize {
-            return None;
-        }
-        self.compact_now()
-    }
-
     fn maybe_auto_compact(&mut self) -> Option<AutoCompactionEvent> {
-        // Gate on the LIVE context size — the most recent call's input counters — not on a
-        // cumulative running total, and count cached input as the context it is.
-        //
-        // The previous gate (`cumulative_usage().input_tokens`) was wrong twice over:
-        //   1. It ignored `cache_read_input_tokens`. With prompt caching a warm call reports
-        //      `input_tokens: 2`, so the counter crawled and compaction never fired however
-        //      large the context grew.
-        //   2. Summing across calls is not a context measurement, and the sum never decreased,
-        //      so once it did trip, every later iteration compacted forever.
-        // Reading the latest turn fixes both: it rises with the real context and falls back
-        // below the threshold as soon as a compaction has done its job.
-        if self.usage_tracker.current_turn_usage().total_input_tokens()
+        if self.usage_tracker.cumulative_usage().input_tokens
             < self.auto_compaction_input_tokens_threshold
         {
             return None;
         }
 
-        self.compact_now()
-    }
-
-    /// Compacts the session unconditionally, returning `None` when nothing actually changed.
-    fn compact_now(&mut self) -> Option<AutoCompactionEvent> {
         let result = compact_session(
             &self.session,
             CompactionConfig {
@@ -780,12 +588,7 @@ where
             },
         );
 
-        // `removed_message_count` alone is the wrong test for "did anything happen": compaction
-        // also trims oversized tool-result payloads in messages it must PRESERVE, and on a
-        // session too short to have anything droppable that trimming is the entire result.
-        // Gating on the count would compute the smaller session and then throw it away.
-        let shrank = result.compacted_session.messages != self.session.messages;
-        if result.removed_message_count == 0 && !shrank {
+        if result.removed_message_count == 0 {
             return None;
         }
 
@@ -906,88 +709,19 @@ where
 /// Reads the automatic compaction threshold from the environment.
 #[must_use]
 pub fn auto_compaction_threshold_from_env() -> u32 {
-    resolve_auto_compaction_threshold(
+    parse_auto_compaction_threshold(
         std::env::var(AUTO_COMPACTION_THRESHOLD_ENV_VAR)
             .ok()
             .as_deref(),
-        std::env::var(CONTEXT_WINDOW_ENV_VAR).ok().as_deref(),
-    )
-}
-
-/// Resolves the threshold from an explicit setting, else from the declared context window.
-///
-/// `DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD` is a 200k-window number. Against a smaller
-/// server it sits above the window entirely, so the pre-request guard can never fire and the
-/// first sign of trouble is the backend rejecting the request. Deriving from the declared window
-/// keeps the guard meaningful without every caller having to compute a second number by hand.
-#[must_use]
-fn resolve_auto_compaction_threshold(explicit: Option<&str>, context_window: Option<&str>) -> u32 {
-    if let Some(threshold) = parse_positive_u32(explicit) {
-        return threshold;
-    }
-    parse_positive_u32(context_window).map_or(
-        DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD,
-        |window| {
-            (u64::from(window) * u64::from(AUTO_COMPACTION_WINDOW_PERCENT) / 100)
-                .try_into()
-                .unwrap_or(DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD)
-        },
     )
 }
 
 #[must_use]
-fn parse_positive_u32(value: Option<&str>) -> Option<u32> {
+fn parse_auto_compaction_threshold(value: Option<&str>) -> u32 {
     value
         .and_then(|raw| raw.trim().parse::<u32>().ok())
-        .filter(|parsed| *parsed > 0)
-}
-
-/// How many auto-continue nudges a single turn may inject. `0` disables the behaviour.
-#[must_use]
-pub fn max_stall_nudges_from_env() -> usize {
-    parse_max_stall_nudges(std::env::var(MAX_STALL_NUDGES_ENV_VAR).ok().as_deref())
-}
-
-#[must_use]
-fn parse_max_stall_nudges(value: Option<&str>) -> usize {
-    value
-        .and_then(|raw| raw.trim().parse::<usize>().ok())
-        .unwrap_or(DEFAULT_MAX_STALL_NUDGES)
-}
-
-/// Concatenated text of an assistant message, ignoring thinking and tool blocks.
-#[must_use]
-fn assistant_text(message: &ConversationMessage) -> String {
-    message
-        .blocks
-        .iter()
-        .filter_map(|block| match block {
-            ContentBlock::Text { text } => Some(text.as_str()),
-            _ => None,
-        })
-        .collect::<Vec<_>>()
-        .join("\n")
-}
-
-/// True when a tool-less reply is a stall rather than a finished turn.
-///
-/// Small local models routinely narrate the next tool call in prose and then emit EOS, which
-/// ends the turn with the announced work never performed. `after_tool_use` additionally treats
-/// a mid-task question as a stall: once tools have run in this turn, stopping to ask for a
-/// go-ahead is the same failure wearing a different hat.
-#[must_use]
-fn is_stalled_reply(text: &str, after_tool_use: bool) -> bool {
-    let Some(last_line) = text.lines().map(str::trim).rfind(|line| !line.is_empty()) else {
-        return false;
-    };
-    let lowered = last_line.to_lowercase();
-
-    if after_tool_use && last_line.ends_with('?') {
-        return true;
-    }
-    PENDING_ACTION_MARKERS
-        .iter()
-        .any(|marker| lowered.contains(marker))
+        .filter(|threshold| *threshold > 0)
+        .unwrap_or(DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD)
 }
 
 fn build_assistant_message(
@@ -1119,13 +853,11 @@ impl ToolExecutor for StaticToolExecutor {
 #[cfg(test)]
 mod tests {
     use super::{
-        assistant_text, build_assistant_message, is_stalled_reply, parse_max_stall_nudges,
-        resolve_auto_compaction_threshold, ApiClient, ApiRequest, AssistantEvent,
-        AutoCompactionEvent, ConversationRuntime, PromptCacheEvent, RuntimeError,
+        build_assistant_message, parse_auto_compaction_threshold, ApiClient, ApiRequest,
+        AssistantEvent, AutoCompactionEvent, ConversationRuntime, PromptCacheEvent, RuntimeError,
         StaticToolExecutor, ToolExecutor, DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD,
-        DEFAULT_MAX_STALL_NUDGES,
     };
-    use crate::compact::{estimate_session_tokens, CompactionConfig};
+    use crate::compact::CompactionConfig;
     use crate::config::{RuntimeFeatureConfig, RuntimeHookConfig};
     use crate::permissions::{
         PermissionMode, PermissionPolicy, PermissionPromptDecision, PermissionPrompter,
@@ -1969,246 +1701,19 @@ mod tests {
         assert_eq!(runtime.session().messages.len(), 2);
     }
 
-    /// Prompt caching reports the bulk of the context as `cache_read_input_tokens` and leaves
-    /// `input_tokens` at a token or two, so a gate that reads `input_tokens` alone never fires
-    /// on a cached session no matter how large the context has grown.
-    #[test]
-    fn auto_compaction_counts_cached_context_toward_threshold() {
-        struct CachedApi;
-        impl ApiClient for CachedApi {
-            fn stream(
-                &mut self,
-                _request: ApiRequest,
-            ) -> Result<Vec<AssistantEvent>, RuntimeError> {
-                Ok(vec![
-                    AssistantEvent::TextDelta("done".to_string()),
-                    AssistantEvent::Usage(TokenUsage {
-                        input_tokens: 2,
-                        output_tokens: 4,
-                        cache_creation_input_tokens: 1_804,
-                        cache_read_input_tokens: 112_639,
-                    }),
-                    AssistantEvent::MessageStop,
-                ])
-            }
-        }
-
-        let mut session = Session::new();
-        session.messages = vec![
-            crate::session::ConversationMessage::user_text("one"),
-            crate::session::ConversationMessage::assistant(vec![ContentBlock::Text {
-                text: "two".to_string(),
-            }]),
-            crate::session::ConversationMessage::user_text("three"),
-            crate::session::ConversationMessage::assistant(vec![ContentBlock::Text {
-                text: "four".to_string(),
-            }]),
-        ];
-
-        let mut runtime = ConversationRuntime::new(
-            session,
-            CachedApi,
-            StaticToolExecutor::new(),
-            PermissionPolicy::new(PermissionMode::DangerFullAccess),
-            vec!["system".to_string()],
-        )
-        .with_auto_compaction_input_tokens_threshold(100_000);
-
-        let summary = runtime
-            .run_turn("trigger", None)
-            .expect("turn should succeed");
-
-        assert_eq!(
-            summary.auto_compaction,
-            Some(AutoCompactionEvent {
-                removed_message_count: 2,
-            })
-        );
-    }
-
-    /// The threshold describes the LIVE context, not a monotonic running total. Once compaction
-    /// has shrunk the context back down, later small turns must not keep compacting.
-    #[test]
-    fn auto_compaction_stops_once_the_context_shrinks_again() {
-        struct ShrinkingApi {
-            calls: u32,
-        }
-        impl ApiClient for ShrinkingApi {
-            fn stream(
-                &mut self,
-                _request: ApiRequest,
-            ) -> Result<Vec<AssistantEvent>, RuntimeError> {
-                let call = self.calls;
-                self.calls += 1;
-                // The first call is over budget; every call after it is small.
-                let input_tokens = if call == 0 { 150_000 } else { 900 };
-                Ok(vec![
-                    AssistantEvent::TextDelta("done".to_string()),
-                    AssistantEvent::Usage(TokenUsage {
-                        input_tokens,
-                        output_tokens: 4,
-                        cache_creation_input_tokens: 0,
-                        cache_read_input_tokens: 0,
-                    }),
-                    AssistantEvent::MessageStop,
-                ])
-            }
-        }
-
-        let mut session = Session::new();
-        session.messages = vec![
-            crate::session::ConversationMessage::user_text("one"),
-            crate::session::ConversationMessage::assistant(vec![ContentBlock::Text {
-                text: "two".to_string(),
-            }]),
-            crate::session::ConversationMessage::user_text("three"),
-            crate::session::ConversationMessage::assistant(vec![ContentBlock::Text {
-                text: "four".to_string(),
-            }]),
-        ];
-
-        let mut runtime = ConversationRuntime::new(
-            session,
-            ShrinkingApi { calls: 0 },
-            // Every turn after a compaction runs the session health probe, which calls
-            // `glob_search`; without it the probe fails the turn before the assertion is reached.
-            StaticToolExecutor::new().register("glob_search", |_| Ok(String::new())),
-            PermissionPolicy::new(PermissionMode::DangerFullAccess),
-            vec!["system".to_string()],
-        )
-        .with_auto_compaction_input_tokens_threshold(100_000);
-
-        let first = runtime.run_turn("trigger", None).expect("first turn");
-        assert!(
-            first.auto_compaction.is_some(),
-            "the over-budget turn should compact"
-        );
-
-        let second = runtime.run_turn("again", None).expect("second turn");
-        assert_eq!(
-            second.auto_compaction, None,
-            "a small turn after compaction must not compact again"
-        );
-        let third = runtime.run_turn("and again", None).expect("third turn");
-        assert_eq!(
-            third.auto_compaction, None,
-            "compaction must not latch on once the threshold has been crossed"
-        );
-    }
-
-    /// Usage-based compaction is post-hoc: it only sees the context AFTER a call returns. A
-    /// large tool result (or a long reasoning block) appended after that measurement can blow
-    /// the window on the very next request, which the provider rejects outright — so there must
-    /// also be a check BEFORE the request goes out, based on a locally estimated session size.
-    #[test]
-    fn auto_compaction_fires_before_the_first_request_when_the_session_is_already_oversized() {
-        struct RecordingApi {
-            largest_request_messages: std::rc::Rc<std::cell::Cell<usize>>,
-        }
-        impl ApiClient for RecordingApi {
-            fn stream(&mut self, request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError> {
-                self.largest_request_messages.set(
-                    self.largest_request_messages
-                        .get()
-                        .max(request.messages.len()),
-                );
-                Ok(vec![
-                    AssistantEvent::TextDelta("done".to_string()),
-                    // Deliberately no Usage event: nothing has been measured yet, which is
-                    // exactly the situation the pre-send check has to cover.
-                    AssistantEvent::MessageStop,
-                ])
-            }
-        }
-
-        // Six messages that are individually large — the shape of a session that has just
-        // absorbed a couple of big file reads.
-        let bulk = "x".repeat(40_000);
-        let mut session = Session::new();
-        for _ in 0..3 {
-            session
-                .messages
-                .push(crate::session::ConversationMessage::user_text(bulk.clone()));
-            session
-                .messages
-                .push(crate::session::ConversationMessage::assistant(vec![
-                    ContentBlock::Text { text: bulk.clone() },
-                ]));
-        }
-        let before = estimate_session_tokens(&session);
-        assert!(
-            before > 24_000,
-            "test fixture must start over the threshold, got {before}"
-        );
-
-        let largest = std::rc::Rc::new(std::cell::Cell::new(0usize));
-        let mut runtime = ConversationRuntime::new(
-            session,
-            RecordingApi {
-                largest_request_messages: std::rc::Rc::clone(&largest),
-            },
-            StaticToolExecutor::new().register("glob_search", |_| Ok(String::new())),
-            PermissionPolicy::new(PermissionMode::DangerFullAccess),
-            vec!["system".to_string()],
-        )
-        .with_auto_compaction_input_tokens_threshold(24_000);
-
-        let summary = runtime
-            .run_turn("trigger", None)
-            .expect("turn should succeed");
-
-        assert!(
-            summary.auto_compaction.is_some(),
-            "an already-oversized session must compact before the request is sent"
-        );
-        assert!(
-            estimate_session_tokens(runtime.session()) < before,
-            "compaction must actually shrink the session"
-        );
-        assert!(
-            largest.get() < 8,
-            "the request must be sent with the compacted history, not the original 7 messages"
-        );
-    }
-
     #[test]
     fn auto_compaction_threshold_defaults_and_parses_values() {
         assert_eq!(
-            resolve_auto_compaction_threshold(None, None),
+            parse_auto_compaction_threshold(None),
             DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD
         );
-        assert_eq!(resolve_auto_compaction_threshold(Some("4321"), None), 4321);
+        assert_eq!(parse_auto_compaction_threshold(Some("4321")), 4321);
         assert_eq!(
-            resolve_auto_compaction_threshold(Some("0"), None),
+            parse_auto_compaction_threshold(Some("0")),
             DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD
         );
         assert_eq!(
-            resolve_auto_compaction_threshold(Some("not-a-number"), None),
-            DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD
-        );
-    }
-
-    #[test]
-    fn auto_compaction_threshold_derives_from_a_declared_context_window() {
-        // 70% of 65536, so the guard sits inside the window instead of 34k above it.
-        assert_eq!(
-            resolve_auto_compaction_threshold(None, Some("65536")),
-            45875
-        );
-    }
-
-    #[test]
-    fn an_explicit_threshold_still_wins_over_the_declared_window() {
-        assert_eq!(
-            resolve_auto_compaction_threshold(Some("48000"), Some("65536")),
-            48000
-        );
-    }
-
-    #[test]
-    fn an_unparseable_context_window_falls_back_to_the_default_threshold() {
-        assert_eq!(
-            resolve_auto_compaction_threshold(None, Some("plenty")),
+            parse_auto_compaction_threshold(Some("not-a-number")),
             DEFAULT_AUTO_COMPACTION_INPUT_TOKENS_THRESHOLD
         );
     }
@@ -2380,146 +1885,6 @@ mod tests {
         assert_eq!(error.to_string(), "unknown tool: missing");
     }
 
-    /// Replays a fixed script of stream outcomes, one per call.
-    struct ScriptedApi {
-        steps: Vec<Result<Vec<AssistantEvent>, String>>,
-        calls: usize,
-    }
-
-    impl ScriptedApi {
-        fn new(steps: Vec<Result<Vec<AssistantEvent>, String>>) -> Self {
-            Self { steps, calls: 0 }
-        }
-    }
-
-    impl ApiClient for ScriptedApi {
-        fn stream(&mut self, _request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError> {
-            let step = self
-                .steps
-                .get(self.calls)
-                .cloned()
-                .unwrap_or_else(|| Err("script exhausted".to_string()));
-            self.calls += 1;
-            step.map_err(RuntimeError::new)
-        }
-    }
-
-    fn tool_call_events(id: &str) -> Vec<AssistantEvent> {
-        vec![
-            AssistantEvent::ToolUse {
-                id: id.to_string(),
-                name: "echo".to_string(),
-                input: "payload".to_string(),
-            },
-            AssistantEvent::MessageStop,
-        ]
-    }
-
-    fn scripted_runtime(
-        steps: Vec<Result<Vec<AssistantEvent>, String>>,
-    ) -> ConversationRuntime<ScriptedApi, StaticToolExecutor> {
-        ConversationRuntime::new(
-            Session::new(),
-            ScriptedApi::new(steps),
-            StaticToolExecutor::new().register("echo", |input| Ok(input.to_string())),
-            PermissionPolicy::new(PermissionMode::DangerFullAccess),
-            vec!["system".to_string()],
-        )
-    }
-
-    #[test]
-    fn a_failed_turn_keeps_the_results_of_tools_that_already_ran() {
-        // given: a turn whose first iteration runs a tool, and whose second call dies
-        let mut runtime = scripted_runtime(vec![
-            Ok(tool_call_events("tool-1")),
-            Err("upstream failed".to_string()),
-        ]);
-
-        // when
-        runtime
-            .run_turn("do the thing", None)
-            .expect_err("the second call fails");
-
-        // then: the executed tool's result is still in the transcript. The side effect happened;
-        // a caller that discards this record will let the model run the same tool again.
-        let tool_results = runtime
-            .session()
-            .messages
-            .iter()
-            .filter(|message| {
-                message
-                    .blocks
-                    .iter()
-                    .any(|block| matches!(block, ContentBlock::ToolResult { .. }))
-            })
-            .count();
-        assert_eq!(tool_results, 1);
-    }
-
-    #[test]
-    fn resume_turn_continues_without_appending_another_user_message() {
-        // given: a session that already carries a user turn and a completed tool result
-        let mut runtime = scripted_runtime(vec![
-            Ok(tool_call_events("tool-1")),
-            Err("upstream failed".to_string()),
-            Ok(vec![
-                AssistantEvent::TextDelta("done".to_string()),
-                AssistantEvent::MessageStop,
-            ]),
-        ]);
-        runtime.run_turn("do the thing", None).expect_err("fails");
-        let user_messages_before = runtime
-            .session()
-            .messages
-            .iter()
-            .filter(|message| message.role == MessageRole::User)
-            .count();
-
-        // when
-        runtime
-            .resume_turn(None)
-            .expect("the resumed turn succeeds");
-
-        // then: the prompt was not repeated
-        let user_messages_after = runtime
-            .session()
-            .messages
-            .iter()
-            .filter(|message| message.role == MessageRole::User)
-            .count();
-        assert_eq!(user_messages_before, user_messages_after);
-    }
-
-    #[test]
-    fn a_stall_nudge_is_recorded_as_a_system_turn_not_a_user_one() {
-        // given: a reply that announces work and stops, so the nudge fires once
-        let mut runtime = nudge_runtime(
-            vec![
-                text_only("Let me check the logs."),
-                text_only("The logs were clean."),
-            ],
-            1,
-        );
-        runtime
-            .run_turn("check the logs", None)
-            .expect("the nudged turn completes");
-
-        // then: exactly one user message — the real one
-        let user_messages = runtime
-            .session()
-            .messages
-            .iter()
-            .filter(|message| message.role == MessageRole::User)
-            .count();
-        assert_eq!(user_messages, 1);
-        assert!(runtime
-            .session()
-            .messages
-            .iter()
-            .any(|message| message.role == MessageRole::System
-                && assistant_text(message).contains("[auto-continue]")));
-    }
-
     #[test]
     fn run_turn_errors_when_max_iterations_is_exceeded() {
         struct LoopingApi;
@@ -2591,136 +1956,4 @@ mod tests {
         // then
         assert_eq!(error.to_string(), "upstream failed");
     }
-
-    fn text_only(text: &str) -> Vec<AssistantEvent> {
-        vec![
-            AssistantEvent::TextDelta(text.to_string()),
-            AssistantEvent::MessageStop,
-        ]
-    }
-
-    struct CountingApi {
-        calls: usize,
-        replies: Vec<Vec<AssistantEvent>>,
-    }
-
-    impl ApiClient for CountingApi {
-        fn stream(&mut self, _request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError> {
-            let reply = self
-                .replies
-                .get(self.calls)
-                .cloned()
-                .unwrap_or_else(|| text_only("Now running the next probe:"));
-            self.calls += 1;
-            Ok(reply)
-        }
-    }
-
-    fn nudge_runtime(
-        replies: Vec<Vec<AssistantEvent>>,
-        max_stall_nudges: usize,
-    ) -> ConversationRuntime<CountingApi, StaticToolExecutor> {
-        ConversationRuntime::new(
-            Session::new(),
-            CountingApi { calls: 0, replies },
-            StaticToolExecutor::new().register("probe", |_| Ok("probe output".to_string())),
-            PermissionPolicy::new(PermissionMode::DangerFullAccess),
-            vec!["system".to_string()],
-        )
-        .with_max_stall_nudges(max_stall_nudges)
-    }
-
-    #[test]
-    fn announced_but_uncalled_tool_is_auto_continued() {
-        // given: the model narrates the next probe instead of calling it
-        let mut runtime = nudge_runtime(
-            vec![
-                text_only("Now running the Ford EEC-V tuner probe (ATSP1):"),
-                vec![
-                    AssistantEvent::ToolUse {
-                        id: "tool-1".to_string(),
-                        name: "probe".to_string(),
-                        input: "atsp1".to_string(),
-                    },
-                    AssistantEvent::MessageStop,
-                ],
-                text_only("No response on ATSP1, which is expected here."),
-            ],
-            3,
-        );
-
-        // when
-        let summary = runtime.run_turn("run the probes", None).expect("turn runs");
-
-        // then: the nudge pulled it back into the loop and the tool actually ran
-        assert_eq!(summary.iterations, 3);
-        assert_eq!(summary.tool_results.len(), 1);
-    }
-
-    #[test]
-    fn nudges_are_bounded_so_a_stuck_model_still_stops() {
-        // given: every reply is an announcement and nothing is ever called
-        let mut runtime = nudge_runtime(Vec::new(), 2);
-
-        // when
-        let summary = runtime.run_turn("run the probes", None).expect("turn runs");
-
-        // then: initial reply plus exactly two nudged retries
-        assert_eq!(summary.iterations, 3);
-        assert!(summary.tool_results.is_empty());
-    }
-
-    #[test]
-    fn a_plain_completion_is_not_nudged() {
-        // given
-        let mut runtime = nudge_runtime(vec![text_only("The DTC scan came back clean.")], 3);
-
-        // when
-        let summary = runtime.run_turn("scan for codes", None).expect("turn runs");
-
-        // then
-        assert_eq!(summary.iterations, 1);
-    }
-
-    #[test]
-    fn zero_budget_disables_auto_continue() {
-        // given
-        let mut runtime = nudge_runtime(vec![text_only("Let me run the DTC scan.")], 0);
-
-        // when
-        let summary = runtime.run_turn("scan for codes", None).expect("turn runs");
-
-        // then
-        assert_eq!(summary.iterations, 1);
-    }
-
-    #[test]
-    fn a_question_stalls_only_after_a_tool_has_run() {
-        assert!(is_stalled_reply("Should I run the DTC scan next?", true));
-        assert!(!is_stalled_reply("Which port is the adapter on?", false));
-    }
-
-    #[test]
-    fn stall_detection_reads_the_last_line_not_the_whole_reply() {
-        // an announcement earlier in the reply does not make a finished turn look stalled
-        assert!(!is_stalled_reply(
-            "Let me check the port.\nThe scan finished with no codes stored.",
-            true
-        ));
-        assert!(is_stalled_reply(
-            "The scan finished.\nNext I'll read the freeze-frame data.",
-            true
-        ));
-    }
-
-    #[test]
-    fn stall_nudge_budget_parses_from_env_value() {
-        // asserted against the literal, not the constant: comparing the parser to the same
-        // constant it falls back to would pass no matter what the default became
-        assert_eq!(DEFAULT_MAX_STALL_NUDGES, 3);
-        assert_eq!(parse_max_stall_nudges(None), 3);
-        assert_eq!(parse_max_stall_nudges(Some("not a number")), 3);
-        assert_eq!(parse_max_stall_nudges(Some(" 5 ")), 5);
-        assert_eq!(parse_max_stall_nudges(Some("0")), 0);
-    }
 }
diff --git a/rust/crates/runtime/src/file_ops.rs b/rust/crates/runtime/src/file_ops.rs
index 6e034f29..7a62447a 100644
--- a/rust/crates/runtime/src/file_ops.rs
+++ b/rust/crates/runtime/src/file_ops.rs
@@ -11,48 +11,8 @@ use serde::{Deserialize, Serialize};
 use walkdir::{DirEntry, WalkDir};
 
 /// Maximum file size that can be read (10 MB).
-///
-/// This is a *process* guard — it stops us slurping a huge or binary blob into memory. It is
-/// not a context guard: 10 MB is on the order of 2.5 M tokens, so it never fires on the files
-/// that actually blow a model's context window. `DEFAULT_READ_LINES` / `MAX_READ_CHARS` below
-/// are the context guard.
 const MAX_READ_SIZE: u64 = 10 * 1024 * 1024;
 
-/// Lines returned by `read_file` when the caller does not pass an explicit `limit`.
-///
-/// This is a *paging* size, not a refusal. An unbounded read is the easiest way for a model to
-/// destroy its own context: one 100 KB source file is ~25 k tokens, which does not fit alongside
-/// a system prompt in a 32 k window. When that happens the backend rejects the whole request and
-/// the session dies — so reading everything at once is what makes it stop. Returning a page plus
-/// `nextOffset` means the read always succeeds and the model can keep going.
-const DEFAULT_READ_LINES: usize = 2000;
-
-/// Hard ceiling on the characters `read_file` returns, applied even when `limit` is explicit.
-///
-/// `DEFAULT_READ_LINES` alone does not bound the payload: minified bundles, JSON blobs and
-/// generated sources routinely put megabytes on a handful of lines. ~64 KB is ~16 k tokens.
-///
-/// That default assumes a large (200 k) context window. Against a small self-hosted backend it
-/// is far too generous: two reads at this size put a request over 47 k tokens, which a 32 k
-/// window rejects outright — and compaction cannot recover it, because the preserved recent
-/// messages ARE the oversized tool results. Override with [`MAX_READ_CHARS_ENV_VAR`].
-const DEFAULT_MAX_READ_CHARS: usize = 64 * 1024;
-
-/// Environment override for [`DEFAULT_MAX_READ_CHARS`], in characters.
-const MAX_READ_CHARS_ENV_VAR: &str = "CLAW_MAX_READ_CHARS";
-
-/// Effective character ceiling for one `read_file` page.
-///
-/// Read per call rather than cached: a long-lived process should pick up a changed budget, and
-/// this runs once per read, not per line.
-fn max_read_chars() -> usize {
-    std::env::var(MAX_READ_CHARS_ENV_VAR)
-        .ok()
-        .and_then(|raw| raw.trim().parse::<usize>().ok())
-        .filter(|chars| *chars > 0)
-        .unwrap_or(DEFAULT_MAX_READ_CHARS)
-}
-
 /// Maximum file size that can be written (10 MB).
 const MAX_WRITE_SIZE: usize = 10 * 1024 * 1024;
 
@@ -120,17 +80,6 @@ pub struct TextFilePayload {
     pub start_line: usize,
     #[serde(rename = "totalLines")]
     pub total_lines: usize,
-    /// True when the file has more lines past this page. Signals the caller that it has NOT seen
-    /// the whole file, so it does not silently reason over a partial view.
-    #[serde(default)]
-    pub truncated: bool,
-    /// Line index to pass back as `offset` to continue reading. Absent once the file is exhausted.
-    #[serde(
-        rename = "nextOffset",
-        default,
-        skip_serializing_if = "Option::is_none"
-    )]
-    pub next_offset: Option<usize>,
 }
 
 /// Output envelope for the `read_file` tool.
@@ -279,28 +228,10 @@ pub fn read_file(
     let content = fs::read_to_string(&absolute_path)?;
     let lines: Vec<&str> = content.lines().collect();
     let start_index = offset.unwrap_or(0).min(lines.len());
-    // An absent `limit` pages rather than reading to EOF: see DEFAULT_READ_LINES.
-    let requested_end = start_index
-        .saturating_add(limit.unwrap_or(DEFAULT_READ_LINES))
-        .min(lines.len());
-
-    // Apply the character ceiling on top of the line window, so a file with very long lines
-    // cannot blow the budget the line cap was meant to enforce. Always yield at least one line,
-    // otherwise an oversized single line would return nothing and the caller could not advance.
-    let mut end_index = start_index;
-    let mut chars = 0usize;
-    let char_ceiling = max_read_chars();
-    for line in &lines[start_index..requested_end] {
-        let next = chars + line.chars().count() + 1;
-        if next > char_ceiling && end_index > start_index {
-            break;
-        }
-        chars = next;
-        end_index += 1;
-    }
-
+    let end_index = limit.map_or(lines.len(), |limit| {
+        start_index.saturating_add(limit).min(lines.len())
+    });
     let selected = lines[start_index..end_index].join("\n");
-    let truncated = end_index < lines.len();
 
     Ok(ReadFileOutput {
         kind: String::from("text"),
@@ -310,8 +241,6 @@ pub fn read_file(
             num_lines: end_index.saturating_sub(start_index),
             start_line: start_index.saturating_add(1),
             total_lines: lines.len(),
-            truncated,
-            next_offset: truncated.then_some(end_index),
         },
     })
 }
@@ -883,18 +812,11 @@ mod tests {
 
     use super::{
         component_contains_glob, derive_glob_walk_root, edit_file, expand_braces, glob_search,
-        grep_search, is_symlink_escape, max_read_chars, normalize_for_comparison, read_file,
+        grep_search, is_symlink_escape, normalize_for_comparison, read_file,
         read_file_in_workspace, write_file, write_file_in_workspace, GrepSearchInput,
-        DEFAULT_MAX_READ_CHARS, DEFAULT_READ_LINES, MAX_READ_CHARS_ENV_VAR, MAX_WRITE_SIZE,
+        MAX_WRITE_SIZE,
     };
 
-    /// Serializes the tests that mutate `CLAW_MAX_READ_CHARS`; env vars are process-global.
-    fn env_lock() -> std::sync::MutexGuard<'static, ()> {
-        static LOCK: std::sync::Mutex<()> = std::sync::Mutex::new(());
-        LOCK.lock()
-            .unwrap_or_else(std::sync::PoisonError::into_inner)
-    }
-
     fn temp_path(name: &str) -> std::path::PathBuf {
         let unique = SystemTime::now()
             .duration_since(UNIX_EPOCH)
@@ -915,132 +837,6 @@ mod tests {
         assert_eq!(read_output.file.content, "two");
     }
 
-    #[test]
-    fn unbounded_read_of_a_large_file_pages_instead_of_returning_everything() {
-        // Regression: an unbounded read used to return the whole file, which on a small-context
-        // backend overflows the window and the request is rejected outright — the session dies.
-        let path = temp_path("paged-read.txt");
-        let total = DEFAULT_READ_LINES + 500;
-        let body = (0..total)
-            .map(|i| format!("line {i}"))
-            .collect::<Vec<_>>()
-            .join("\n");
-        write_file(path.to_string_lossy().as_ref(), &body).expect("write should succeed");
-
-        let first = read_file(path.to_string_lossy().as_ref(), None, None).expect("first page");
-        assert_eq!(first.file.num_lines, DEFAULT_READ_LINES);
-        assert_eq!(first.file.total_lines, total);
-        assert!(first.file.truncated, "caller must be told it is partial");
-        assert_eq!(first.file.next_offset, Some(DEFAULT_READ_LINES));
-        assert!(first.file.content.starts_with("line 0\n"));
-
-        // The advertised next_offset must actually resume where the last page stopped.
-        let second = read_file(
-            path.to_string_lossy().as_ref(),
-            first.file.next_offset,
-            None,
-        )
-        .expect("second page");
-        assert_eq!(second.file.num_lines, 500);
-        assert!(!second.file.truncated, "the tail is the final page");
-        assert_eq!(second.file.next_offset, None);
-        assert!(second
-            .file
-            .content
-            .starts_with(&format!("line {DEFAULT_READ_LINES}\n")));
-    }
-
-    #[test]
-    fn char_ceiling_bounds_files_whose_lines_are_enormous() {
-        // A line cap alone does not bound the payload: minified bundles put megabytes on a few
-        // lines, so the byte ceiling has to apply too — and must still yield forward progress.
-        let _guard = env_lock();
-        std::env::remove_var(MAX_READ_CHARS_ENV_VAR);
-        let path = temp_path("long-lines.txt");
-        let huge = "x".repeat(DEFAULT_MAX_READ_CHARS);
-        let body = format!("{huge}\n{huge}\n{huge}");
-        write_file(path.to_string_lossy().as_ref(), &body).expect("write should succeed");
-
-        let page = read_file(path.to_string_lossy().as_ref(), None, None).expect("first page");
-        assert_eq!(page.file.num_lines, 1, "one oversized line still advances");
-        assert!(page.file.truncated);
-        assert_eq!(page.file.next_offset, Some(1));
-
-        // An explicit limit must not be able to defeat the ceiling.
-        let greedy = read_file(path.to_string_lossy().as_ref(), None, Some(3)).expect("greedy");
-        assert_eq!(greedy.file.num_lines, 1);
-        assert!(greedy.file.truncated);
-    }
-
-    /// The 64 KB default is a 200 k-context number. A small self-hosted backend must be able to
-    /// shrink it, or two reads overflow a 32 k window in a single turn.
-    #[test]
-    fn read_char_ceiling_is_configurable_via_the_environment() {
-        let _guard = env_lock();
-        let path = temp_path("configurable-ceiling.txt");
-        // 40 lines of 100 chars = ~4 KB: far under the default ceiling, over a 1 KB one.
-        let body = (0..40)
-            .map(|_| "y".repeat(100))
-            .collect::<Vec<_>>()
-            .join("\n");
-        write_file(path.to_string_lossy().as_ref(), &body).expect("write should succeed");
-
-        std::env::remove_var(MAX_READ_CHARS_ENV_VAR);
-        let whole = read_file(path.to_string_lossy().as_ref(), None, None).expect("default read");
-        assert_eq!(
-            whole.file.num_lines, 40,
-            "default ceiling returns the file whole"
-        );
-        assert!(!whole.file.truncated);
-
-        std::env::set_var(MAX_READ_CHARS_ENV_VAR, "1024");
-        let clipped = read_file(path.to_string_lossy().as_ref(), None, None).expect("clipped read");
-        std::env::remove_var(MAX_READ_CHARS_ENV_VAR);
-        assert!(
-            clipped.file.num_lines < 40,
-            "a smaller ceiling must actually clip, got {} lines",
-            clipped.file.num_lines
-        );
-        assert!(
-            clipped.file.truncated,
-            "a clipped page must report truncated"
-        );
-        assert_eq!(
-            clipped.file.next_offset,
-            Some(clipped.file.num_lines),
-            "the caller must be told where to resume"
-        );
-    }
-
-    #[test]
-    fn read_char_ceiling_ignores_junk_and_zero_values() {
-        let _guard = env_lock();
-        for value in ["", "0", "-5", "not-a-number"] {
-            std::env::set_var(MAX_READ_CHARS_ENV_VAR, value);
-            assert_eq!(
-                max_read_chars(),
-                DEFAULT_MAX_READ_CHARS,
-                "{value:?} must fall back to the default rather than disabling reads"
-            );
-        }
-        std::env::set_var(MAX_READ_CHARS_ENV_VAR, "24000");
-        assert_eq!(max_read_chars(), 24_000);
-        std::env::remove_var(MAX_READ_CHARS_ENV_VAR);
-        assert_eq!(max_read_chars(), DEFAULT_MAX_READ_CHARS);
-    }
-
-    #[test]
-    fn small_files_are_returned_whole_and_not_marked_truncated() {
-        let path = temp_path("small-read.txt");
-        write_file(path.to_string_lossy().as_ref(), "one\ntwo\nthree").expect("write");
-
-        let output = read_file(path.to_string_lossy().as_ref(), None, None).expect("read");
-        assert_eq!(output.file.content, "one\ntwo\nthree");
-        assert_eq!(output.file.num_lines, 3);
-        assert!(!output.file.truncated);
-        assert_eq!(output.file.next_offset, None);
-    }
-
     #[test]
     fn edits_file_contents() {
         let path = temp_path("edit.txt");
diff --git a/rust/crates/runtime/src/prompt.rs b/rust/crates/runtime/src/prompt.rs
index ae5bf66b..98683112 100644
--- a/rust/crates/runtime/src/prompt.rs
+++ b/rust/crates/runtime/src/prompt.rs
@@ -42,25 +42,7 @@ pub const SYSTEM_PROMPT_DYNAMIC_BOUNDARY: &str = "__SYSTEM_PROMPT_DYNAMIC_BOUNDA
 pub const FRONTIER_MODEL_NAME: &str = "Claude Opus 4.6";
 const MAX_INSTRUCTION_FILE_CHARS: usize = 4_000;
 const MAX_TOTAL_INSTRUCTION_CHARS: usize = 12_000;
-/// Character budget for the git diff snapshot embedded in the system prompt.
-///
-/// This lives in the *system prompt*, so its cost is paid on every session whose
-/// working tree has changed — and a diff changes on essentially every edit. The
-/// previous 50_000 budget was four times the entire instruction-file budget and
-/// could add ~15_000 tokens to the prompt from a single modified file, which is
-/// affordable against a hosted frontier model and ruinous against a local one.
-///
-/// Override with `CLAW_MAX_GIT_DIFF_CHARS`. `0` drops the diff snapshot entirely;
-/// git status and the recent-commit list are unaffected.
-const DEFAULT_MAX_GIT_DIFF_CHARS: usize = 4_000;
-const MAX_GIT_DIFF_CHARS_ENV_VAR: &str = "CLAW_MAX_GIT_DIFF_CHARS";
-
-fn max_git_diff_chars() -> usize {
-    std::env::var(MAX_GIT_DIFF_CHARS_ENV_VAR)
-        .ok()
-        .and_then(|value| value.trim().parse().ok())
-        .unwrap_or(DEFAULT_MAX_GIT_DIFF_CHARS)
-}
+const MAX_GIT_DIFF_CHARS: usize = 50_000;
 
 /// Neutral identity for the model family line in generated prompts.
 #[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
@@ -516,15 +498,8 @@ fn read_git_diff(cwd: &Path) -> Option<String> {
 }
 
 fn truncate_diff(mut diff: String) -> String {
-    let budget = max_git_diff_chars();
-    // A zero budget means "omit the diff", not "truncate to nothing" -- returning
-    // an empty string here would still push an empty "Git diff snapshot:" heading
-    // into the prompt.
-    if budget == 0 {
-        return String::new();
-    }
-    if diff.len() > budget {
-        let mut end = budget;
+    if diff.len() > MAX_GIT_DIFF_CHARS {
+        let mut end = MAX_GIT_DIFF_CHARS;
         while !diff.is_char_boundary(end) {
             end -= 1;
         }
@@ -783,7 +758,6 @@ fn get_simple_doing_tasks_section() -> String {
         "Do not add speculative abstractions, compatibility shims, or unrelated cleanup.".to_string(),
         "Do not create files unless they are required to complete the task.".to_string(),
         "If an approach fails, diagnose the failure before switching tactics.".to_string(),
-        "Act in the turn you plan in: when the next step is a tool call, make the call. Never end a turn describing a step you have not taken, and do not stop to ask for a go-ahead on work already requested.".to_string(),
         "Be careful not to introduce security vulnerabilities such as command injection, XSS, or SQL injection.".to_string(),
         "Report outcomes faithfully: if verification fails or was not run, say so explicitly.".to_string(),
     ]);
@@ -808,8 +782,7 @@ mod tests {
         collapse_blank_lines, display_context_path, normalize_instruction_content,
         render_instruction_content, render_instruction_files, truncate_diff,
         truncate_instruction_content, ContextFile, ModelFamilyIdentity, ProjectContext,
-        SystemPromptBuilder, DEFAULT_MAX_GIT_DIFF_CHARS, MAX_GIT_DIFF_CHARS_ENV_VAR,
-        SYSTEM_PROMPT_DYNAMIC_BOUNDARY,
+        SystemPromptBuilder, MAX_GIT_DIFF_CHARS, SYSTEM_PROMPT_DYNAMIC_BOUNDARY,
     };
     use crate::config::ConfigLoader;
     use std::fs;
@@ -1471,69 +1444,33 @@ mod tests {
         assert!(rendered.contains("Project rules"));
     }
 
-    /// Serializes the tests that read or mutate `CLAW_MAX_GIT_DIFF_CHARS`; env vars
-    /// are process-global and the default-budget tests fail if another test leaves
-    /// an override set.
-    fn diff_env_lock() -> std::sync::MutexGuard<'static, ()> {
-        static LOCK: std::sync::Mutex<()> = std::sync::Mutex::new(());
-        LOCK.lock()
-            .unwrap_or_else(std::sync::PoisonError::into_inner)
-    }
-
     #[test]
     fn truncate_diff_preserves_short_content() {
-        let _guard = diff_env_lock();
-        std::env::remove_var(MAX_GIT_DIFF_CHARS_ENV_VAR);
         let short = "a".repeat(1_000);
         let result = truncate_diff(short.clone());
         assert_eq!(result, short);
         assert!(!result.contains("[diff truncated"));
     }
 
-    #[test]
-    fn truncate_diff_honors_env_override() {
-        let _guard = diff_env_lock();
-        std::env::set_var(MAX_GIT_DIFF_CHARS_ENV_VAR, "100");
-        let result = truncate_diff("z".repeat(1_000));
-        std::env::remove_var(MAX_GIT_DIFF_CHARS_ENV_VAR);
-        let marker = "\n\n... [diff truncated — too large for system prompt]";
-        assert!(result.ends_with(marker));
-        assert_eq!(result.len() - marker.len(), 100);
-    }
-
-    #[test]
-    fn truncate_diff_zero_budget_omits_the_snapshot_entirely() {
-        // Zero must yield nothing at all -- a truncated-to-empty body would still
-        // drag a "Git diff snapshot:" heading and the truncation marker into the
-        // prompt, which is the opposite of what the operator asked for.
-        let _guard = diff_env_lock();
-        std::env::set_var(MAX_GIT_DIFF_CHARS_ENV_VAR, "0");
-        let result = truncate_diff("z".repeat(1_000));
-        std::env::remove_var(MAX_GIT_DIFF_CHARS_ENV_VAR);
-        assert!(result.is_empty());
-    }
-
     #[test]
     fn truncate_diff_caps_oversized_content() {
-        let _guard = diff_env_lock();
-        std::env::remove_var(MAX_GIT_DIFF_CHARS_ENV_VAR);
-        let large = "x".repeat(DEFAULT_MAX_GIT_DIFF_CHARS + 5_000);
+        let large = "x".repeat(MAX_GIT_DIFF_CHARS + 5_000);
         let result = truncate_diff(large);
         assert!(result.contains("... [diff truncated — too large for system prompt]"));
-        // The body before the marker must be at most DEFAULT_MAX_GIT_DIFF_CHARS bytes
+        // The body before the marker must be at most MAX_GIT_DIFF_CHARS bytes
         let marker = "\n\n... [diff truncated — too large for system prompt]";
         let body_len = result.len() - marker.len();
-        assert!(body_len <= DEFAULT_MAX_GIT_DIFF_CHARS);
+        assert!(body_len <= MAX_GIT_DIFF_CHARS);
     }
 
     #[test]
     fn truncate_diff_respects_utf8_char_boundaries() {
-        // Build a string where DEFAULT_MAX_GIT_DIFF_CHARS falls in the middle of a
+        // Build a string where MAX_GIT_DIFF_CHARS falls in the middle of a
         // multi-byte character (U+1F600 = 4 bytes in UTF-8).
-        let prefix_len = DEFAULT_MAX_GIT_DIFF_CHARS - 2;
+        let prefix_len = MAX_GIT_DIFF_CHARS - 2;
         let mut input = "a".repeat(prefix_len);
         // Append a 4-byte emoji so bytes [prefix_len..prefix_len+4] are the
-        // emoji.  DEFAULT_MAX_GIT_DIFF_CHARS lands at prefix_len+2, inside the emoji.
+        // emoji.  MAX_GIT_DIFF_CHARS lands at prefix_len+2, inside the emoji.
         input.push('\u{1F600}');
         input.push_str(&"b".repeat(10_000));
 
@@ -1545,7 +1482,7 @@ mod tests {
         // inside it would be invalid UTF-8.
         let marker = "\n\n... [diff truncated — too large for system prompt]";
         let body = &result[..result.len() - marker.len()];
-        assert!(body.len() <= DEFAULT_MAX_GIT_DIFF_CHARS);
+        assert!(body.len() <= MAX_GIT_DIFF_CHARS);
         assert!(body.is_char_boundary(body.len()));
     }
 }
diff --git a/rust/crates/runtime/src/session.rs b/rust/crates/runtime/src/session.rs
index 61cca8c8..2ecfd97d 100644
--- a/rust/crates/runtime/src/session.rs
+++ b/rust/crates/runtime/src/session.rs
@@ -718,20 +718,6 @@ impl ConversationMessage {
         }
     }
 
-    /// Text the harness injected on its own initiative, not something the user typed.
-    ///
-    /// Reaches the model as an ordinary turn — the wire protocol has nowhere else to put it — but
-    /// stays labelled in the transcript, so a replay, an export, or a compaction summary does not
-    /// present the harness's own prompting back as the user's words.
-    #[must_use]
-    pub fn system_text(text: impl Into<String>) -> Self {
-        Self {
-            role: MessageRole::System,
-            blocks: vec![ContentBlock::Text { text: text.into() }],
-            usage: None,
-        }
-    }
-
     #[must_use]
     pub fn assistant(blocks: Vec<ContentBlock>) -> Self {
         Self {
diff --git a/rust/crates/runtime/src/trident.rs b/rust/crates/runtime/src/trident.rs
index 07576822..2346a4ea 100644
--- a/rust/crates/runtime/src/trident.rs
+++ b/rust/crates/runtime/src/trident.rs
@@ -29,7 +29,7 @@ impl Default for TridentConfig {
 }
 
 /// Statistics from a Trident compaction run.
-#[derive(Debug, Clone, PartialEq, Eq, Default)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct TridentStats {
     pub superseded_count: usize,
     pub collapsed_chains: usize,
@@ -41,6 +41,21 @@ pub struct TridentStats {
     pub final_message_count: usize,
 }
 
+impl Default for TridentStats {
+    fn default() -> Self {
+        Self {
+            superseded_count: 0,
+            collapsed_chains: 0,
+            messages_collapsed: 0,
+            clusters_found: 0,
+            messages_clustered: 0,
+            tokens_saved_estimate: 0,
+            original_message_count: 0,
+            final_message_count: 0,
+        }
+    }
+}
+
 impl TridentStats {
     pub fn format_report(&self) -> String {
         let compression = if self.final_message_count > 0 {
@@ -177,7 +192,7 @@ fn stage1_supersede(messages: &[ConversationMessage]) -> (Vec<ConversationMessag
 
     let mut obsolete_indices: BTreeSet<usize> = BTreeSet::new();
 
-    for ops in file_ops.values() {
+    for (_path, ops) in &file_ops {
         if ops.len() < 2 {
             continue;
         }
@@ -190,8 +205,10 @@ fn stage1_supersede(messages: &[ConversationMessage]) -> (Vec<ConversationMessag
 
         if let Some(last_write) = last_write_idx {
             for op in ops {
-                if op.index < last_write
-                    && matches!(op.op_type, FileOp::Read | FileOp::Write | FileOp::Edit)
+                if op.op_type == FileOp::Read && op.index < last_write {
+                    obsolete_indices.insert(op.index);
+                } else if (op.op_type == FileOp::Write || op.op_type == FileOp::Edit)
+                    && op.index < last_write
                 {
                     obsolete_indices.insert(op.index);
                 }
@@ -308,7 +325,7 @@ fn stage2_collapse(
                     usage: None,
                 });
             } else {
-                result.append(&mut buffer);
+                result.extend(buffer.drain(..));
             }
             buffer.clear();
             result.push(msg.clone());
@@ -459,7 +476,7 @@ fn stage3_cluster(
     }
 
     let total_clustered: usize = cluster_assignments.len();
-    let clusters_found = cluster_id;
+    let clusters_found = cluster_id as usize;
 
     let mut result: Vec<ConversationMessage> = Vec::new();
     let mut cluster_buffers: BTreeMap<usize, Vec<usize>> = BTreeMap::new();
@@ -660,7 +677,7 @@ fn truncate_text(text: &str, max_chars: usize) -> String {
 mod tests {
     use super::*;
     use crate::compact::CompactionConfig;
-    use crate::session::{ContentBlock, ConversationMessage, Session};
+    use crate::session::{ContentBlock, ConversationMessage, MessageRole, Session};
 
     #[test]
     fn stage1_removes_obsolete_file_reads() {
@@ -719,7 +736,7 @@ mod tests {
     fn stage2_collapses_chatty_messages() {
         let mut messages = vec![];
         for i in 0..6 {
-            messages.push(ConversationMessage::user_text(format!("ok {i}")));
+            messages.push(ConversationMessage::user_text(&format!("ok {i}")));
             messages.push(ConversationMessage::assistant(vec![ContentBlock::Text {
                 text: format!("got {i}"),
             }]));
@@ -750,9 +767,9 @@ mod tests {
                 },
             ]));
             messages.push(ConversationMessage::tool_result(
-                format!("read_{i}"),
+                &format!("read_{i}"),
                 "read_file",
-                format!(r#"{{"path":"src/{i}.rs","content":"data {i}"}}"#),
+                &format!(r#"{{"path":"src/{i}.rs","content":"data {i}"}}"#),
                 false,
             ));
         }
diff --git a/rust/crates/runtime/src/usage.rs b/rust/crates/runtime/src/usage.rs
index ceafa7d0..9241f7c2 100644
--- a/rust/crates/runtime/src/usage.rs
+++ b/rust/crates/runtime/src/usage.rs
@@ -89,19 +89,6 @@ impl TokenUsage {
             + self.cache_read_input_tokens
     }
 
-    /// Total tokens the provider had to read to serve this call, i.e. the live size of the
-    /// context window.
-    ///
-    /// `input_tokens` alone is NOT that number. With prompt caching a warm call reports
-    /// `input_tokens: 2` and puts the real bulk in `cache_read_input_tokens`, so anything
-    /// budgeting against the context window must sum all three input counters.
-    #[must_use]
-    pub fn total_input_tokens(self) -> u32 {
-        self.input_tokens
-            .saturating_add(self.cache_creation_input_tokens)
-            .saturating_add(self.cache_read_input_tokens)
-    }
-
     #[must_use]
     pub fn estimate_cost_usd(self) -> UsageCostEstimate {
         self.estimate_cost_usd_with_pricing(ModelPricing::default_sonnet_tier())
@@ -256,41 +243,6 @@ mod tests {
         assert_eq!(tracker.cumulative_usage().total_tokens(), 48);
     }
 
-    #[test]
-    fn total_input_tokens_includes_cached_context() {
-        // The shape a warm prompt-cached call actually reports: input_tokens is ~nothing and
-        // the real context size is in the cache counters.
-        let cached = TokenUsage {
-            input_tokens: 2,
-            output_tokens: 1_133,
-            cache_creation_input_tokens: 1_453,
-            cache_read_input_tokens: 111_186,
-        };
-        assert_eq!(cached.total_input_tokens(), 112_641);
-        // Output tokens are not part of the input budget.
-        assert_ne!(cached.total_input_tokens(), cached.total_tokens());
-
-        // A backend without prompt caching reports the whole prompt as input_tokens.
-        let uncached = TokenUsage {
-            input_tokens: 29_056,
-            output_tokens: 73,
-            cache_creation_input_tokens: 0,
-            cache_read_input_tokens: 0,
-        };
-        assert_eq!(uncached.total_input_tokens(), 29_056);
-    }
-
-    #[test]
-    fn total_input_tokens_saturates_instead_of_overflowing() {
-        let usage = TokenUsage {
-            input_tokens: u32::MAX,
-            output_tokens: 0,
-            cache_creation_input_tokens: u32::MAX,
-            cache_read_input_tokens: u32::MAX,
-        };
-        assert_eq!(usage.total_input_tokens(), u32::MAX);
-    }
-
     #[test]
     fn computes_cost_summary_lines() {
         let usage = TokenUsage {
diff --git a/rust/crates/rusty-claude-cli/src/main.rs b/rust/crates/rusty-claude-cli/src/main.rs
index 1de5e233..cda89fa1 100644
--- a/rust/crates/rusty-claude-cli/src/main.rs
+++ b/rust/crates/rusty-claude-cli/src/main.rs
@@ -74,22 +74,6 @@ use tools::{
 
 const DEFAULT_MODEL: &str = "anthropic/claude-opus-4-7";
 
-/// Ceiling on model/tool round trips within one turn.
-///
-/// `ConversationRuntime` defaults to `usize::MAX`, which for the interactive and `-p` paths means
-/// no ceiling at all: a model that keeps re-reading the same file loops until the user kills it.
-/// Spawned subagents have always been bounded; this gives the top-level loop the same treatment.
-const DEFAULT_MAX_TURN_ITERATIONS: usize = 32;
-const MAX_TURN_ITERATIONS_ENV_VAR: &str = "CLAW_MAX_TURN_ITERATIONS";
-
-fn max_turn_iterations_from_env() -> usize {
-    std::env::var(MAX_TURN_ITERATIONS_ENV_VAR)
-        .ok()
-        .and_then(|raw| raw.trim().parse::<usize>().ok())
-        .filter(|iterations| *iterations > 0)
-        .unwrap_or(DEFAULT_MAX_TURN_ITERATIONS)
-}
-
 /// #148: Model provenance for `claw status` JSON/text output. Records where
 /// the resolved model string came from so claws don't have to re-read argv
 /// to audit whether their `--model` flag was honored vs falling back to env
@@ -1957,7 +1941,9 @@ fn parse_args(args: &[String]) -> Result<CliAction, String> {
         // Only reject for known top-level subcommands that don't use compact.
         let first = rest[0].as_str();
         if is_known_top_level_subcommand(first) && first != "prompt" {
-            return Err("invalid_flag_value: --compact is only supported with prompt mode.\nUsage: claw --compact \"<prompt>\" or echo \"<prompt>\" | claw --compact".to_string());
+            return Err(format!(
+                "invalid_flag_value: --compact is only supported with prompt mode.\nUsage: claw --compact \"<prompt>\" or echo \"<prompt>\" | claw --compact"
+            ));
         }
     }
 
@@ -3161,11 +3147,10 @@ fn print_model_validation_warning_status(
         usage,
         permission_mode,
         context,
-        &StatusJsonExtras {
-            allowed_tools,
-            format_selection: Some(&format_selection),
-            ..StatusJsonExtras::default()
-        },
+        None,
+        None,
+        allowed_tools,
+        Some(&format_selection),
     );
     let object = value
         .as_object_mut()
@@ -3241,7 +3226,9 @@ fn parse_system_prompt_args(
                 })?;
                 // #99: validate --date is a plausible date string (no newlines, reasonable length)
                 if value.contains('\n') || value.contains('\r') {
-                    return Err("invalid_flag_value: --date value contains invalid characters.\nUsage: --date <YYYY-MM-DD>".to_string());
+                    return Err(format!(
+                        "invalid_flag_value: --date value contains invalid characters.\nUsage: --date <YYYY-MM-DD>"
+                    ));
                 }
                 if value.len() > 20 {
                     return Err(format!(
@@ -3478,7 +3465,11 @@ impl DiagnosticCheck {
 
     fn json_value(&self) -> Value {
         // Derive a stable snake_case id from the check name for machine-readable keying (#704).
-        let id = self.name.to_ascii_lowercase().replace([' ', '-'], "_");
+        let id = self
+            .name
+            .to_ascii_lowercase()
+            .replace(' ', "_")
+            .replace('-', "_");
         let mut value = Map::from_iter([
             ("id".to_string(), Value::String(id.clone())),
             (
@@ -6659,8 +6650,10 @@ fn run_resume_command(
                     },
                     default_permission_mode().as_str(),
                     &context,
-                    // #148: resumed sessions don't have flag provenance
-                    &StatusJsonExtras::default(),
+                    None, // #148: resumed sessions don't have flag provenance
+                    None,
+                    None,
+                    None,
                 )),
             })
         }
@@ -6841,15 +6834,16 @@ fn run_resume_command(
         }
         SlashCommand::Plugins { action, target } => {
             // Only list is supported in resume mode (no runtime to reload)
-            if let Some(action @ ("install" | "uninstall" | "enable" | "disable" | "update")) =
-                action.as_deref()
-            {
-                // #777: use interactive_only: prefix + \n hint so #776's classify/split
-                // emits error_kind:interactive_only + non-null hint instead of unknown+null.
-                // Orchestrators can now detect this and switch to a live REPL instead of retrying.
-                return Err(format!(
-                    "interactive_only: /plugins {action} requires a live session to reload the plugin runtime.\nStart `claw` and run `/plugins {action}` inside the REPL, or use `claw plugins {action}` as a direct CLI command."
-                ).into());
+            match action.as_deref() {
+                Some(action @ ("install" | "uninstall" | "enable" | "disable" | "update")) => {
+                    // #777: use interactive_only: prefix + \n hint so #776's classify/split
+                    // emits error_kind:interactive_only + non-null hint instead of unknown+null.
+                    // Orchestrators can now detect this and switch to a live REPL instead of retrying.
+                    return Err(format!(
+                        "interactive_only: /plugins {action} requires a live session to reload the plugin runtime.\nStart `claw` and run `/plugins {action}` inside the REPL, or use `claw plugins {action}` as a direct CLI command."
+                    ).into());
+                }
+                _ => {}
             }
             let cwd = env::current_dir()?;
             let payload = plugins_command_payload_for(
@@ -7913,15 +7907,6 @@ impl LiveCli {
                 Ok(())
             }
             Err(error) => {
-                // Salvage the transcript before the failed runtime is torn down.
-                //
-                // `prepare_turn_runtime` handed `run_turn` a CLONE of the session, and the turn
-                // mutated only that clone — appending the user message, each assistant reply, and
-                // a tool_result for every tool that actually executed. Dropping the clone throws
-                // all of that away while the side effects of those tools remain on disk, so the
-                // retry below would re-issue them against a session that shows no sign they ever
-                // ran. Adopting the clone keeps the record and the reality in step.
-                *self.runtime.session_mut() = runtime.session().clone();
                 runtime.shutdown_plugins()?;
                 // Same ownership rule as the success arm: `fail` clears the current
                 // line, so it may only do so when the emitter stopped on a line
@@ -7948,17 +7933,37 @@ impl LiveCli {
                 // This eliminates the need for users to manually run /compact when they
                 // hit context limits - the recovery happens automatically.
                 //
-                // Detection: the API layer classified this when it still had the typed error and
-                // the outgoing request in hand — see `AnthropicRuntimeClient::runtime_error_from_api`.
-                // It is deliberately NOT re-derived from the rendered message here: compaction
-                // discards conversation history, and the substrings that used to gate it
-                // ("error decoding response body", "Failed to parse input at pos") are emitted by
-                // ordinary transport failures as well as by overflow, so a dropped connection cost
-                // the session its transcript.
+                // Detection: We look for "context_window" or "Context window" in the error
+                // message, which covers error types like:
+                // - "context_window_blocked"
+                // - "Context window blocked"
+                // - "This model's maximum context length is X tokens..."
                 // ============================================================================
 
                 let error_str = error.to_string();
-                if error.is_context_window_failure() {
+                // Detect context window overflow. Some providers (e.g. OpenAI-compat backends)
+                // return 400 with "no parseable body" instead of a proper context_length_exceeded
+                // error when the request is too large to even parse — treat that as context overflow too.
+                // Also detect model-specific context error markers (e.g. llama.cpp returns
+                // "Context size has been exceeded." / "exceed_context_size_error" / "exceeds the available context size").
+                let is_context_window = error_str.contains("context_window")
+                    || error_str.contains("Context window")
+                    || error_str.contains("no parseable body")
+                    || error_str.contains("exceed_context_size")
+                    || error_str.contains("exceeds the available context size")
+                    || error_str
+                        .to_ascii_lowercase()
+                        .contains("context size has been exceeded");
+
+                // Also treat "assistant stream produced no content" and reqwest decode failures
+                // as recoverable errors that may benefit from auto-compaction. Some backends (e.g.
+                // llama.cpp) return a non-SSE HTTP 500 body when context overflows, causing
+                // reqwest to fail with "error decoding response body" — treat that as context overflow too.
+                let is_no_content = error_str.contains("assistant stream produced no content")
+                    || error_str.contains("Failed to parse input at pos")
+                    || error_str.contains("error decoding response body");
+
+                if is_context_window || is_no_content {
                     // If the error tells us the server's actual context window, adapt our
                     // auto-compaction threshold so future auto-compact-trigger checks are accurate.
                     if let Some(window) = extract_context_window_tokens_from_error(&error_str) {
@@ -7978,7 +7983,8 @@ impl LiveCli {
                     let max_compact_rounds = 4;
                     let preserve_schedule = [4, 2, 1, 0];
 
-                    for (round, &preserve) in preserve_schedule.iter().enumerate() {
+                    for round in 0..max_compact_rounds {
+                        let preserve = preserve_schedule[round];
                         println!(
                             "  Auto-compacting session (round {}/{}, preserving {} recent messages)...",
                             round + 1,
@@ -8025,11 +8031,7 @@ impl LiveCli {
                         drop(hook_abort_monitor);
 
                         let mut rp = CliPermissionPrompter::new(self.permission_mode);
-                        // Resume, do not replay. The salvaged session already carries this turn's
-                        // user message and every tool result that completed before the failure;
-                        // re-running `run_turn(input, ..)` would duplicate the prompt and invite a
-                        // second execution of tools that are not idempotent.
-                        match new_runtime.resume_turn(Some(&mut rp)) {
+                        match new_runtime.run_turn(input, Some(&mut rp)) {
                             Ok(summary) => {
                                 self.replace_runtime(new_runtime)?;
                                 if !terminal_tail.at_line_start() {
@@ -8056,7 +8058,20 @@ impl LiveCli {
                             }
                             Err(retry_error) => {
                                 let retry_str = retry_error.to_string();
-                                if retry_error.is_context_window_failure()
+                                let still_context_window = retry_str.contains("context_window")
+                                    || retry_str.contains("Context window")
+                                    || retry_str.contains("no parseable body")
+                                    || retry_str.contains("exceed_context_size")
+                                    || retry_str.contains("exceeds the available context size")
+                                    || retry_str
+                                        .to_ascii_lowercase()
+                                        .contains("context size has been exceeded");
+                                let still_no_content = retry_str
+                                    .contains("assistant stream produced no content")
+                                    || retry_str.contains("Failed to parse input at pos")
+                                    || retry_str.contains("error decoding response body");
+
+                                if (still_context_window || still_no_content)
                                     && round + 1 < max_compact_rounds
                                 {
                                     // If the retry error reveals the context window, adapt threshold.
@@ -8783,8 +8798,8 @@ impl LiveCli {
         let cwd = env::current_dir()?;
         // #803: reject flag-shaped tokens in list filter for BOTH text and JSON modes.
         // Previously the guard was JSON-only (#793); text mode silently returned empty success.
-        if action == Some("list") {
-            if let Some(filter) = target {
+        if action.as_deref() == Some("list") {
+            if let Some(filter) = target.as_deref() {
                 if filter.starts_with('-') {
                     if matches!(output_format, CliOutputFormat::Json) {
                         // ROADMAP #817: this is a handled local inventory parse error.
@@ -9779,49 +9794,31 @@ fn print_status_snapshot(
                 usage,
                 permission_mode.mode.as_str(),
                 &context,
-                &StatusJsonExtras {
-                    provenance: Some(&provenance),
-                    permission_provenance: Some(&permission_mode),
-                    allowed_tools,
-                    format_selection: Some(&format_selection),
-                },
+                Some(&provenance),
+                Some(&permission_mode),
+                allowed_tools,
+                Some(&format_selection),
             ))?
         ),
     }
     Ok(())
 }
 
-/// Optional provenance and selection inputs for [`status_json_value`].
-///
-/// Grouped into a struct rather than trailing positional parameters: they are all
-/// `Option<&_>` and most callers pass `None` for most of them, which makes a
-/// positional tail easy to transpose silently.
-///
-/// `provenance` (#148) drives the `model_source` field ("flag" | "env" | "config" |
-/// "default") and `model_raw` (user input before alias resolution, or null when the
-/// source is "default"). Callers without provenance (legacy resume paths) leave it
-/// `None`, in which case both fields are omitted.
-#[derive(Default)]
-struct StatusJsonExtras<'a> {
-    provenance: Option<&'a ModelProvenance>,
-    permission_provenance: Option<&'a PermissionModeProvenance>,
-    allowed_tools: Option<&'a AllowedToolSet>,
-    format_selection: Option<&'a OutputFormatSelection>,
-}
-
 fn status_json_value(
     model: Option<&str>,
     usage: StatusUsage,
     permission_mode: &str,
     context: &StatusContext,
-    extras: &StatusJsonExtras<'_>,
+    // #148: optional provenance for `model` field. Surfaces `model_source`
+    // ("flag" | "env" | "config" | "default") and `model_raw` (user input
+    // before alias resolution, or null when source is "default"). Callers
+    // that don't have provenance (legacy resume paths) pass None, in which
+    // case both new fields are omitted.
+    provenance: Option<&ModelProvenance>,
+    permission_provenance: Option<&PermissionModeProvenance>,
+    allowed_tools: Option<&AllowedToolSet>,
+    format_selection: Option<&OutputFormatSelection>,
 ) -> serde_json::Value {
-    let StatusJsonExtras {
-        provenance,
-        permission_provenance,
-        allowed_tools,
-        format_selection,
-    } = *extras;
     // #143: top-level `status` marker so claws can distinguish
     // a clean run from a degraded run (config parse failed but other fields
     // are still populated). `config_load_error` carries the parse-error string
@@ -10303,7 +10300,9 @@ fn sandbox_json_value(status: &runtime::SandboxStatus) -> serde_json::Value {
     //        (#731: "not supported on macOS" is a degraded state, not a hard error;
     //         filesystem_active:true means partial containment is working)
     // error = enabled but unsupported AND no filesystem sandbox either (nothing active)
-    let top_status = if !status.enabled || status.active {
+    let top_status = if !status.enabled {
+        "ok"
+    } else if status.active {
         "ok"
     } else if status.supported {
         "warn"
@@ -10678,20 +10677,18 @@ fn render_doctor_help_json() -> serde_json::Value {
 }
 
 /// #683-#692: extract structured metadata from help prose
-/// Parsed fields of a help topic: usage, purpose, output description, formats,
-/// related topics, aliases, local-only, requires-credentials.
-type HelpMetadata = (
-    Option<String>,
-    Option<String>,
-    Option<String>,
-    Option<Vec<String>>,
-    Option<Vec<String>>,
-    Option<Vec<String>>,
-    bool,
-    bool,
-);
-
-fn extract_help_metadata(topic: LocalHelpTopic) -> HelpMetadata {
+fn extract_help_metadata(
+    topic: LocalHelpTopic,
+) -> (
+    Option<String>,      // usage
+    Option<String>,      // purpose
+    Option<String>,      // output description
+    Option<Vec<String>>, // formats
+    Option<Vec<String>>, // related
+    Option<Vec<String>>, // aliases
+    bool,                // local_only
+    bool,                // requires_credentials
+) {
     let text = render_help_topic(topic);
     let mut usage = None;
     let mut purpose = None;
@@ -12735,8 +12732,7 @@ fn build_runtime_with_plugin_state(
         policy,
         system_prompt,
         &feature_config,
-    )
-    .with_max_iterations(max_turn_iterations_from_env());
+    );
     if emit_output {
         runtime = runtime.with_hook_progress_reporter(Box::new(CliHookProgressReporter));
     }
@@ -13150,49 +13146,7 @@ impl ApiClient for AnthropicRuntimeClient {
     }
 }
 
-/// How full a request must be, as a percentage of the declared context window, before an
-/// unreadable failure is taken to mean the window overflowed.
-const AMBIGUOUS_FAILURE_WINDOW_PERCENT: u64 = 85;
-
-/// True when a request was close enough to the window that an otherwise unreadable failure is
-/// most likely an overflow.
-///
-/// This is the piece that lets transport errors be classified without matching on their prose.
-/// A backend can answer an oversized request with a non-SSE 500 that reqwest reports as
-/// "error decoding response body"; the same string also appears when the connection simply
-/// dropped. What separates them is not the text, it is whether the request we just sent had any
-/// room left. Requires a declared window — with none, every request looks small and this
-/// correctly returns false.
-fn request_fills_context_window(request: &MessageRequest) -> bool {
-    let Some(limit) = api::model_token_limit(&request.model) else {
-        return false;
-    };
-    let estimated =
-        api::estimate_message_request_input_tokens(request).saturating_add(request.max_tokens);
-    u64::from(estimated) * 100
-        >= u64::from(limit.context_window_tokens) * AMBIGUOUS_FAILURE_WINDOW_PERCENT
-}
-
 impl AnthropicRuntimeClient {
-    /// Converts an API failure into a runtime error, carrying the overflow verdict with it.
-    ///
-    /// The verdict is made here, where the error still has its type and the request is still in
-    /// hand, rather than reconstructed downstream from the rendered message.
-    fn runtime_error_from_api(
-        &self,
-        error: &api::ApiError,
-        request: &MessageRequest,
-    ) -> RuntimeError {
-        let message = format_user_visible_api_error(&self.session_id, error);
-        if error.is_context_window_failure()
-            || (error.is_ambiguous_transport_failure() && request_fills_context_window(request))
-        {
-            RuntimeError::context_window(message)
-        } else {
-            RuntimeError::new(message)
-        }
-    }
-
     /// Consume a single streaming response, optionally applying a stall
     /// timeout on the first event for post-tool continuations.
     #[allow(clippy::too_many_lines)]
@@ -13205,7 +13159,9 @@ impl AnthropicRuntimeClient {
             .client
             .stream_message(message_request)
             .await
-            .map_err(|error| self.runtime_error_from_api(&error, message_request))?;
+            .map_err(|error| {
+                RuntimeError::new(format_user_visible_api_error(&self.session_id, &error))
+            })?;
         let mut stdout = io::stdout();
         let mut sink = io::sink();
         let mut tracked = TailTrackingWriter::new(&mut stdout, self.terminal_tail.clone());
@@ -13227,8 +13183,9 @@ impl AnthropicRuntimeClient {
         loop {
             let next = if apply_stall_timeout && !received_any_event {
                 match tokio::time::timeout(POST_TOOL_STALL_TIMEOUT, stream.next_event()).await {
-                    Ok(inner) => inner
-                        .map_err(|error| self.runtime_error_from_api(&error, message_request))?,
+                    Ok(inner) => inner.map_err(|error| {
+                        RuntimeError::new(format_user_visible_api_error(&self.session_id, &error))
+                    })?,
                     Err(_elapsed) => {
                         return Err(RuntimeError::new(
                             "post-tool stall: model did not respond within timeout",
@@ -13236,10 +13193,9 @@ impl AnthropicRuntimeClient {
                     }
                 }
             } else {
-                stream
-                    .next_event()
-                    .await
-                    .map_err(|error| self.runtime_error_from_api(&error, message_request))?
+                stream.next_event().await.map_err(|error| {
+                    RuntimeError::new(format_user_visible_api_error(&self.session_id, &error))
+                })?
             };
 
             let Some(event) = next else {
@@ -13379,7 +13335,9 @@ impl AnthropicRuntimeClient {
                 ..message_request.clone()
             })
             .await
-            .map_err(|error| self.runtime_error_from_api(&error, message_request))?;
+            .map_err(|error| {
+                RuntimeError::new(format_user_visible_api_error(&self.session_id, &error))
+            })?;
         let mut events = response_to_events(response, out)?;
         push_prompt_cache_record(&self.client, &mut events);
         Ok(events)
@@ -13503,8 +13461,8 @@ fn format_context_window_blocked_error(session_id: &str, error: &api::ApiError)
             ));
             lines.push(format!("  Context window   {context_window_tokens} tokens"));
         }
-        api::ApiError::Api(details) => {
-            let detail = details.message.as_deref().unwrap_or(&details.body).trim();
+        api::ApiError::Api { message, body, .. } => {
+            let detail = message.as_deref().unwrap_or(body).trim();
             if !detail.is_empty() {
                 lines.push(format!(
                     "  Detail           {}",
@@ -13514,7 +13472,7 @@ fn format_context_window_blocked_error(session_id: &str, error: &api::ApiError)
         }
         api::ApiError::RetriesExhausted { last_error, .. } => {
             let detail = match last_error.as_ref() {
-                api::ApiError::Api(details) => details.message.as_deref().unwrap_or(&details.body),
+                api::ApiError::Api { message, body, .. } => message.as_deref().unwrap_or(body),
                 other => return format_context_window_blocked_error(session_id, other),
             }
             .trim();
@@ -14532,37 +14490,39 @@ fn convert_messages(messages: &[ConversationMessage]) -> Vec<InputMessage> {
             let content = message
                 .blocks
                 .iter()
-                .map(|block| match block {
-                    ContentBlock::Text { text } => InputContentBlock::Text { text: text.clone() },
+                .filter_map(|block| match block {
+                    ContentBlock::Text { text } => {
+                        Some(InputContentBlock::Text { text: text.clone() })
+                    }
                     ContentBlock::Thinking {
                         thinking,
                         signature,
                     } => {
                         // 保留 Thinking 块：OpenAI 兼容协议会把它转成 reasoning_content 字段
                         // 回传给 DeepSeek V4（避免 400 "reasoning_content must be passed back" 错误）
-                        InputContentBlock::Thinking {
+                        Some(InputContentBlock::Thinking {
                             thinking: thinking.clone(),
                             signature: signature.clone(),
-                        }
+                        })
                     }
-                    ContentBlock::ToolUse { id, name, input } => InputContentBlock::ToolUse {
+                    ContentBlock::ToolUse { id, name, input } => Some(InputContentBlock::ToolUse {
                         id: id.clone(),
                         name: name.clone(),
                         input: serde_json::from_str(input)
                             .unwrap_or_else(|_| serde_json::json!({ "raw": input })),
-                    },
+                    }),
                     ContentBlock::ToolResult {
                         tool_use_id,
                         output,
                         is_error,
                         ..
-                    } => InputContentBlock::ToolResult {
+                    } => Some(InputContentBlock::ToolResult {
                         tool_use_id: tool_use_id.clone(),
                         content: vec![ToolResultContentBlock::Text {
                             text: output.clone(),
                         }],
                         is_error: *is_error,
-                    },
+                    }),
                 })
                 .collect::<Vec<_>>();
             (!content.is_empty()).then(|| InputMessage {
@@ -14815,7 +14775,7 @@ mod tests {
         SessionLifecycleSummary, SlashCommand, StatusUsage, TerminalTail, TmuxPaneSnapshot,
         DEFAULT_MODEL, LATEST_SESSION_REFERENCE, STUB_COMMANDS,
     };
-    use api::{ApiError, ApiErrorDetails, MessageResponse, OutputContentBlock, Usage};
+    use api::{ApiError, MessageResponse, OutputContentBlock, Usage};
     use plugins::{
         PluginManager, PluginManagerConfig, PluginTool, PluginToolDefinition, PluginToolPermission,
     };
@@ -14860,7 +14820,7 @@ mod tests {
 
     #[test]
     fn opaque_provider_wrapper_surfaces_failure_class_session_and_trace() {
-        let error = ApiError::Api(Box::new(ApiErrorDetails {
+        let error = ApiError::Api {
             status: "500".parse().expect("status"),
             error_type: Some("api_error".to_string()),
             message: Some(
@@ -14872,7 +14832,7 @@ mod tests {
             retryable: true,
             suggested_action: None,
             retry_after: None,
-}));
+};
 
         let rendered = format_user_visible_api_error("session-issue-22", &error);
         assert!(rendered.contains("provider_internal"));
@@ -14884,7 +14844,7 @@ mod tests {
     fn retry_exhaustion_uses_retry_failure_class_for_generic_provider_wrapper() {
         let error = ApiError::RetriesExhausted {
             attempts: 3,
-            last_error: Box::new(ApiError::Api(Box::new(ApiErrorDetails {
+            last_error: Box::new(ApiError::Api {
                 status: "502".parse().expect("status"),
                 error_type: Some("api_error".to_string()),
                 message: Some(
@@ -14896,7 +14856,7 @@ mod tests {
                 retryable: true,
                 suggested_action: None,
                 retry_after: None,
-}))),
+}),
         };
 
         let rendered = format_user_visible_api_error("session-issue-22", &error);
@@ -14949,7 +14909,7 @@ mod tests {
 
     #[test]
     fn provider_context_window_errors_are_reframed_with_same_guidance() {
-        let error = ApiError::Api(Box::new(ApiErrorDetails {
+        let error = ApiError::Api {
             status: "400".parse().expect("status"),
             error_type: Some("invalid_request_error".to_string()),
             message: Some(
@@ -14961,7 +14921,7 @@ mod tests {
             retryable: false,
             suggested_action: None,
             retry_after: None,
-}));
+};
 
         let rendered = format_user_visible_api_error("session-issue-32", &error);
         assert!(rendered.contains("context_window_blocked"), "{rendered}");
@@ -14983,7 +14943,7 @@ mod tests {
 
     #[test]
     fn openai_configured_limit_errors_are_rendered_as_context_window_guidance() {
-        let error = ApiError::Api(Box::new(ApiErrorDetails {
+        let error = ApiError::Api {
             status: "400".parse().expect("status"),
             error_type: Some("invalid_request_error".to_string()),
             message: Some(
@@ -14995,7 +14955,7 @@ mod tests {
             retryable: false,
             suggested_action: None,
             retry_after: None,
-        }));
+        };
 
         let rendered = format_user_visible_api_error("session-issue-32", &error);
         assert!(rendered.contains("Context window blocked"), "{rendered}");
@@ -15021,7 +14981,7 @@ mod tests {
     fn retry_wrapped_context_window_errors_keep_recovery_guidance() {
         let error = ApiError::RetriesExhausted {
             attempts: 2,
-            last_error: Box::new(ApiError::Api(Box::new(ApiErrorDetails {
+            last_error: Box::new(ApiError::Api {
                 status: "413".parse().expect("status"),
                 error_type: Some("invalid_request_error".to_string()),
                 message: Some("Request is too large for this model's context window.".to_string()),
@@ -15030,7 +14990,7 @@ mod tests {
                 retryable: false,
                 suggested_action: None,
                 retry_after: None,
-            }))),
+            }),
         };
 
         let rendered = format_user_visible_api_error("session-issue-32", &error);
@@ -15077,54 +15037,11 @@ mod tests {
         );
     }
 
-    /// Serialises tests that mutate process-global state, and isolates them from the
-    /// developer's real `~/.claw`.
-    ///
-    /// `parse_args` resolves defaults — notably `permissions.defaultMode` — through the
-    /// user-scope config, which `default_config_home()` reads from `CLAW_CONFIG_HOME`,
-    /// falling back to `$HOME/.claw`. Without an override, these tests therefore assert
-    /// against whatever the machine running them happens to have configured: a
-    /// `defaultMode` of `dontAsk` there resolves to `DangerFullAccess` and turns a dozen
-    /// `WorkspaceWrite` assertions red. Point the config home at a fresh empty directory
-    /// so "no user config" is the state under test, and restore the caller's value on drop.
-    ///
-    /// Tests that need a *populated* config home can still set `CLAW_CONFIG_HOME`
-    /// themselves after taking this guard; the guard restores the real value afterwards.
-    struct EnvGuard {
-        _lock: MutexGuard<'static, ()>,
-        config_home: PathBuf,
-        previous_config_home: Option<std::ffi::OsString>,
-    }
-
-    impl Drop for EnvGuard {
-        fn drop(&mut self) {
-            match self.previous_config_home.take() {
-                Some(previous) => std::env::set_var("CLAW_CONFIG_HOME", previous),
-                None => std::env::remove_var("CLAW_CONFIG_HOME"),
-            }
-            // Best effort: a leftover temp dir must never fail a test.
-            let _ = std::fs::remove_dir_all(&self.config_home);
-        }
-    }
-
-    fn env_lock() -> EnvGuard {
+    fn env_lock() -> MutexGuard<'static, ()> {
         static LOCK: OnceLock<Mutex<()>> = OnceLock::new();
-        let lock = LOCK
-            .get_or_init(|| Mutex::new(()))
+        LOCK.get_or_init(|| Mutex::new(()))
             .lock()
-            .unwrap_or_else(std::sync::PoisonError::into_inner);
-
-        // Deliberately empty: the point is that no user settings.json is discoverable.
-        let config_home = temp_dir();
-        std::fs::create_dir_all(&config_home).expect("isolated config home should be creatable");
-        let previous_config_home = std::env::var_os("CLAW_CONFIG_HOME");
-        std::env::set_var("CLAW_CONFIG_HOME", &config_home);
-
-        EnvGuard {
-            _lock: lock,
-            config_home,
-            previous_config_home,
-        }
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
     }
 
     fn with_current_dir<T>(cwd: &Path, f: impl FnOnce() -> T) -> T {
@@ -15851,8 +15768,6 @@ mod tests {
 
     #[test]
     fn removed_login_and_logout_subcommands_error_helpfully() {
-        // Asserts a `Default`-sourced permission mode, so it must not see a user config.
-        let _guard = env_lock();
         let login = parse_args(&["login".to_string()]).expect_err("login should be removed");
         assert!(login.contains("ANTHROPIC_API_KEY"));
         let logout = parse_args(&["logout".to_string()]).expect_err("logout should be removed");
@@ -16480,7 +16395,10 @@ mod tests {
             usage,
             "workspace-write",
             &context,
-            &super::StatusJsonExtras::default(),
+            None,
+            None,
+            None,
+            None,
         );
         assert_eq!(
             json.get("status").and_then(|v| v.as_str()),
@@ -16552,10 +16470,10 @@ mod tests {
             usage,
             "workspace-write",
             &context,
-            &super::StatusJsonExtras {
-                allowed_tools: Some(&allowed),
-                ..super::StatusJsonExtras::default()
-            },
+            None,
+            None,
+            Some(&allowed),
+            None,
         );
         assert_eq!(
             restricted_json
@@ -16585,7 +16503,10 @@ mod tests {
             usage,
             "workspace-write",
             &clean_context,
-            &super::StatusJsonExtras::default(),
+            None,
+            None,
+            None,
+            None,
         );
         assert_eq!(
             clean_json.get("status").and_then(|v| v.as_str()),
@@ -17533,7 +17454,7 @@ mod tests {
         for action in ["remove", "uninstall", "delete"] {
             assert_eq!(
                 parse_args(&["skills".to_string(), action.to_string()])
-                    .unwrap_or_else(|_| panic!("skills {action} should parse")),
+                    .expect(&format!("skills {action} should parse")),
                 CliAction::Skills {
                     args: Some(action.to_string()),
                     output_format: CliOutputFormat::Text,
@@ -18487,7 +18408,10 @@ mod tests {
             },
             "workspace-write",
             &context,
-            &super::StatusJsonExtras::default(),
+            None,
+            None,
+            None,
+            None,
         );
 
         assert_eq!(
@@ -19761,6 +19685,7 @@ UU conflicted.rs",
             "openai/gpt-5".to_string(),
             false,
             false,
+            TerminalTail::new(),
             None,
             GlobalToolRegistry::builtin(),
             None,
@@ -19820,6 +19745,7 @@ UU conflicted.rs",
             "qwen-plus".to_string(),
             false,
             false,
+            TerminalTail::new(),
             None,
             GlobalToolRegistry::builtin(),
             None,
diff --git a/rust/crates/rusty-claude-cli/src/setup_wizard.rs b/rust/crates/rusty-claude-cli/src/setup_wizard.rs
index aa315dd6..c2f7b6ff 100644
--- a/rust/crates/rusty-claude-cli/src/setup_wizard.rs
+++ b/rust/crates/rusty-claude-cli/src/setup_wizard.rs
@@ -2,6 +2,8 @@ use std::io::{self, IsTerminal, Write};
 
 use runtime::{save_user_provider_settings, ConfigLoader, RuntimeProviderConfig};
 
+use serde_json;
+
 const PROVIDERS: &[(&str, &str, &str)] = &[
     ("1", "Anthropic", "anthropic"),
     ("2", "xAI / Grok", "xai"),
diff --git a/rust/crates/rusty-claude-cli/tests/output_format_contract.rs b/rust/crates/rusty-claude-cli/tests/output_format_contract.rs
index f620797e..8984675e 100644
--- a/rust/crates/rusty-claude-cli/tests/output_format_contract.rs
+++ b/rust/crates/rusty-claude-cli/tests/output_format_contract.rs
@@ -451,16 +451,11 @@ fn direct_resume_safe_slash_commands_route_to_local_json_actions_831() {
         .output()
         .expect("git init should launch");
 
-    // `/sandbox`'s status reflects the host's real sandbox capability, so it is the one
-    // entry with more than one legitimate value: "ok" where namespace isolation works,
-    // "warn" where it is unsupported and only the filesystem sandbox is active (#731).
-    // This test is about #831 routing — that these commands produce a local JSON action
-    // instead of `interactive_only` — not about the kernel the suite happens to run on.
-    for (command, expected_kind, expected_statuses) in [
-        ("/version", "version", &["ok"][..]),
-        ("/sandbox", "sandbox", &["ok", "warn"][..]),
-        ("/diff", "diff", &["ok"][..]),
-        ("/status", "status", &["ok"][..]),
+    for (command, expected_kind, expected_status) in [
+        ("/version", "version", "ok"),
+        ("/sandbox", "sandbox", "warn"),
+        ("/diff", "diff", "ok"),
+        ("/status", "status", "ok"),
     ] {
         let output = run_claw(&root, &["--output-format", "json", command], &[]);
         assert!(
@@ -475,9 +470,9 @@ fn direct_resume_safe_slash_commands_route_to_local_json_actions_831() {
             .unwrap_or_else(|_| panic!("{command} must emit JSON (#831), got: {stdout:?}"));
 
         assert_eq!(parsed["kind"], expected_kind, "{command} kind: {parsed}");
-        assert!(
-            expected_statuses.contains(&parsed["status"].as_str().unwrap_or_default()),
-            "{command} status should be one of {expected_statuses:?}: {parsed}"
+        assert_eq!(
+            parsed["status"], expected_status,
+            "{command} status: {parsed}"
         );
         assert_ne!(
             parsed["error_kind"], "interactive_only",
@@ -1012,13 +1007,13 @@ fn inventory_commands_emit_structured_json_when_requested() {
     assert!(
         !plugins
             .as_object()
-            .is_some_and(|o| o.contains_key("reload_runtime")),
+            .map_or(false, |o| o.contains_key("reload_runtime")),
         "plugins list should not include reload_runtime"
     );
     assert!(
         !plugins
             .as_object()
-            .is_some_and(|o| o.contains_key("target")),
+            .map_or(false, |o| o.contains_key("target")),
         "plugins list should not include target"
     );
     // #703: structured summary replaces prose message
@@ -1712,13 +1707,13 @@ fn resumed_inventory_commands_emit_structured_json_when_requested() {
     assert!(
         !plugins
             .as_object()
-            .is_some_and(|o| o.contains_key("reload_runtime")),
+            .map_or(false, |o| o.contains_key("reload_runtime")),
         "plugins list should not include reload_runtime"
     );
     assert!(
         !plugins
             .as_object()
-            .is_some_and(|o| o.contains_key("target")),
+            .map_or(false, |o| o.contains_key("target")),
         "plugins list should not include target"
     );
     assert!(
@@ -2951,7 +2946,7 @@ fn prompt_empty_arg_json_stdout_missing_prompt_823() {
         "claw prompt empty arg must retain abort action (#823); got: {parsed}"
     );
     assert!(
-        parsed["hint"].as_str().is_some_and(|h| !h.is_empty()),
+        parsed["hint"].as_str().map_or(false, |h| !h.is_empty()),
         "claw prompt empty arg missing_prompt hint must be non-empty (#823)"
     );
 }
@@ -2989,9 +2984,9 @@ fn flag_value_errors_have_error_kind_and_hint_756() {
         "invalid --reasoning-effort must be invalid_flag_value (#756): {parsed}"
     );
     assert!(
-        parsed["hint"]
-            .as_str()
-            .is_some_and(|h| h.contains("low") || h.contains("medium") || h.contains("high")),
+        parsed["hint"].as_str().map_or(false, |h| h.contains("low")
+            || h.contains("medium")
+            || h.contains("high")),
         "hint must mention valid values (#756): {parsed}"
     );
 
@@ -3017,7 +3012,7 @@ fn flag_value_errors_have_error_kind_and_hint_756() {
         "missing --model value must be missing_flag_value (#756): {parsed2}"
     );
     assert!(
-        parsed2["hint"].as_str().is_some_and(|h| !h.is_empty()),
+        parsed2["hint"].as_str().map_or(false, |h| !h.is_empty()),
         "missing --model hint must be non-empty (#756): {parsed2}"
     );
 }
@@ -3261,7 +3256,7 @@ fn short_p_flag_swallows_no_flags_755() {
         "flag-like token after -p must be rejected as missing_prompt (#755): {parsed2}"
     );
     assert!(
-        parsed2["hint"].as_str().is_some_and(|h| !h.is_empty()),
+        parsed2["hint"].as_str().map_or(false, |h| !h.is_empty()),
         "missing_prompt hint must be non-empty (#755)"
     );
 }
@@ -3403,7 +3398,7 @@ fn config_unsupported_section_json_hint_741() {
         assert!(
             parsed["supported_sections"]
                 .as_array()
-                .is_some_and(|a| !a.is_empty()),
+                .map_or(false, |a| !a.is_empty()),
             "config {section} JSON must include supported_sections (#741)"
         );
     }
@@ -3460,7 +3455,7 @@ fn export_json_has_kind_702() {
     // On success stdout has kind:export; on failure stderr has type:error.
     // Either way, both envelopes must be valid JSON.
     let stdout = String::from_utf8_lossy(&output.stdout);
-    let _stderr = String::from_utf8_lossy(&output.stderr)
+    let stderr = String::from_utf8_lossy(&output.stderr)
         .lines()
         .filter(|l| l.starts_with('{'))
         .collect::<Vec<_>>()
@@ -3552,8 +3547,8 @@ fn config_parse_error_has_typed_error_kind_and_hint_764() {
         !output.status.success(),
         "malformed settings.json should cause non-zero exit"
     );
-    let _stdout = String::from_utf8_lossy(&output.stdout);
-    let _stderr = String::from_utf8_lossy(&output.stderr);
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let json_line = stdout
         .lines()
@@ -3587,8 +3582,8 @@ fn login_logout_removed_subcommands_have_error_kind_and_hint_765() {
             !output.status.success(),
             "claw {subcmd} should exit non-zero"
         );
-        let _stdout = String::from_utf8_lossy(&output.stdout);
-        let _stderr = String::from_utf8_lossy(&output.stderr);
+        let stdout = String::from_utf8_lossy(&output.stdout);
+        let stderr = String::from_utf8_lossy(&output.stderr);
         let stdout = String::from_utf8_lossy(&output.stdout);
         let json_line = stdout
             .lines()
@@ -3727,8 +3722,8 @@ fn resume_non_slash_trailing_arg_has_typed_error_kind_and_hint_768() {
         !output.status.success(),
         "claw --resume latest compact should exit non-zero"
     );
-    let _stdout = String::from_utf8_lossy(&output.stdout);
-    let _stderr = String::from_utf8_lossy(&output.stderr);
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let json_line = stdout
         .lines()
@@ -3767,8 +3762,8 @@ fn session_with_unknown_subcommand_returns_interactive_only_not_credentials_767(
             !output.status.success(),
             "claw session {sub} should exit non-zero"
         );
-        let _stdout = String::from_utf8_lossy(&output.stdout);
-        let _stderr = String::from_utf8_lossy(&output.stderr);
+        let stdout = String::from_utf8_lossy(&output.stdout);
+        let stderr = String::from_utf8_lossy(&output.stderr);
         let stdout = String::from_utf8_lossy(&output.stdout);
         let json_line = stdout
             .lines()
@@ -3821,7 +3816,7 @@ fn slash_only_verbs_with_args_return_interactive_only_not_credentials_770() {
             "claw {} should exit non-zero",
             args.join(" ")
         );
-        let _stdout = String::from_utf8_lossy(&output.stdout);
+        let stdout = String::from_utf8_lossy(&output.stdout);
         let stderr = String::from_utf8_lossy(&output.stderr);
         let stdout = String::from_utf8_lossy(&output.stdout);
         let json_line = stdout
@@ -3863,8 +3858,8 @@ fn agents_plugins_mcp_unknown_subcommand_have_hint_774() {
     {
         let output = run_claw(&root, &["--output-format", "json", "agents", "bogus"], &[]);
         assert!(!output.status.success(), "agents bogus should fail");
-        let _stdout = String::from_utf8_lossy(&output.stdout);
-        let _stderr = String::from_utf8_lossy(&output.stderr);
+        let stdout = String::from_utf8_lossy(&output.stdout);
+        let stderr = String::from_utf8_lossy(&output.stderr);
         let stdout = String::from_utf8_lossy(&output.stdout);
         let json_line = stdout
             .lines()
@@ -3887,8 +3882,8 @@ fn agents_plugins_mcp_unknown_subcommand_have_hint_774() {
     {
         let output = run_claw(&root, &["--output-format", "json", "plugins", "bogus"], &[]);
         assert!(!output.status.success(), "plugins bogus should fail");
-        let _stdout = String::from_utf8_lossy(&output.stdout);
-        let _stderr = String::from_utf8_lossy(&output.stderr);
+        let stdout = String::from_utf8_lossy(&output.stdout);
+        let stderr = String::from_utf8_lossy(&output.stderr);
         let stdout = String::from_utf8_lossy(&output.stdout);
         let json_line = stdout
             .lines()
@@ -3907,7 +3902,7 @@ fn agents_plugins_mcp_unknown_subcommand_have_hint_774() {
     {
         let output = run_claw(&root, &["--output-format", "json", "mcp", "bogus"], &[]);
         assert!(!output.status.success(), "mcp bogus should fail");
-        let _stdout = String::from_utf8_lossy(&output.stdout);
+        let stdout = String::from_utf8_lossy(&output.stdout);
         let stderr = String::from_utf8_lossy(&output.stderr);
         let stdout = String::from_utf8_lossy(&output.stdout);
         let json_str = if stdout.trim().starts_with('{') {
@@ -4022,7 +4017,7 @@ fn interactive_only_guard_batch_769_to_771() {
             "claw {} should exit non-zero",
             args.join(" ")
         );
-        let _stdout = String::from_utf8_lossy(&output.stdout);
+        let stdout = String::from_utf8_lossy(&output.stdout);
         let stderr = String::from_utf8_lossy(&output.stderr);
         let stdout = String::from_utf8_lossy(&output.stdout);
         let json_line = stdout
@@ -4086,7 +4081,7 @@ fn resume_plugin_mutations_are_typed_interactive_only_777() {
             !output.status.success(),
             "/plugins {mutation} in resume mode should exit non-zero"
         );
-        let _stdout = String::from_utf8_lossy(&output.stdout);
+        let stdout = String::from_utf8_lossy(&output.stdout);
         let stderr = String::from_utf8_lossy(&output.stderr);
         let stdout = String::from_utf8_lossy(&output.stdout);
         let json_line = stdout
@@ -4143,7 +4138,7 @@ fn resume_skills_invocation_is_typed_interactive_only_779() {
         !output.status.success(),
         "/skills <skill> in resume mode should exit non-zero"
     );
-    let _stdout = String::from_utf8_lossy(&output.stdout);
+    let stdout = String::from_utf8_lossy(&output.stdout);
     let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let json_line = stdout
@@ -4184,8 +4179,8 @@ fn acp_unsupported_invocation_has_hint_782() {
 
     let output = run_claw(&root, &["--output-format", "json", "acp", "start"], &[]);
     assert!(!output.status.success(), "acp start should fail");
-    let _stdout = String::from_utf8_lossy(&output.stdout);
-    let _stderr = String::from_utf8_lossy(&output.stderr);
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let json_line = stdout
         .lines()
@@ -4222,7 +4217,7 @@ fn init_json_envelope_has_hint_and_already_initialized_783() {
     // Fresh init — already_initialized should be false, hint should mention CLAUDE.md
     let output = run_claw(&root, &["--output-format", "json", "init"], &[]);
     assert!(output.status.success(), "init should succeed");
-    let _stdout = String::from_utf8_lossy(&output.stdout);
+    let stdout = String::from_utf8_lossy(&output.stdout);
     let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let raw = if stdout.trim_start().starts_with('{') {
@@ -4291,7 +4286,7 @@ fn init_json_envelope_has_hint_and_already_initialized_783() {
     // Idempotent re-init — already_initialized should be true
     let output2 = run_claw(&root, &["--output-format", "json", "init"], &[]);
     assert!(output2.status.success(), "re-init should succeed");
-    let _stdout2 = String::from_utf8_lossy(&output2.stdout);
+    let stdout2 = String::from_utf8_lossy(&output2.stdout);
     let stderr2 = String::from_utf8_lossy(&output2.stderr);
     let stdout2 = String::from_utf8_lossy(&output2.stdout);
     let raw2 = if stdout2.trim_start().starts_with('{') {
@@ -4372,7 +4367,7 @@ fn export_arg_errors_have_typed_kind_and_hint_784() {
         &[],
     );
     assert!(!out1.status.success(), "--output with no value should fail");
-    let _stderr1 = String::from_utf8_lossy(&out1.stderr);
+    let stderr1 = String::from_utf8_lossy(&out1.stderr);
     let stdout1 = String::from_utf8_lossy(&out1.stdout);
     let j1: serde_json::Value = stdout1
         .lines()
@@ -4399,7 +4394,7 @@ fn export_arg_errors_have_typed_kind_and_hint_784() {
         &[],
     );
     assert!(!out2.status.success(), "extra positional should fail");
-    let _stderr2 = String::from_utf8_lossy(&out2.stderr);
+    let stderr2 = String::from_utf8_lossy(&out2.stderr);
     let stdout2 = String::from_utf8_lossy(&out2.stdout);
     let j2: serde_json::Value = stdout2
         .lines()
@@ -4436,7 +4431,7 @@ fn unknown_subcommand_returns_typed_kind_785() {
     // "dump" is close enough to "dump-manifests" to trigger the typo suggestion path
     let output = run_claw(&root, &["--output-format", "json", "dump"], &[]);
     assert!(!output.status.success(), "unknown subcommand should fail");
-    let _stderr = String::from_utf8_lossy(&output.stderr);
+    let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let j: serde_json::Value = stdout
         .lines()
@@ -4484,7 +4479,7 @@ fn dump_manifests_missing_dir_has_typed_kind_and_hint_786() {
         &[],
     );
     assert!(!out1.status.success());
-    let _stderr1 = String::from_utf8_lossy(&out1.stderr);
+    let stderr1 = String::from_utf8_lossy(&out1.stderr);
     let stdout1 = String::from_utf8_lossy(&out1.stdout);
     let j1: serde_json::Value = stdout1
         .lines()
@@ -4516,7 +4511,7 @@ fn dump_manifests_missing_dir_has_typed_kind_and_hint_786() {
         &[],
     );
     assert!(!out2.status.success());
-    let _stderr2 = String::from_utf8_lossy(&out2.stderr);
+    let stderr2 = String::from_utf8_lossy(&out2.stderr);
     let stdout2 = String::from_utf8_lossy(&out2.stdout);
     let j2: serde_json::Value = stdout2
         .lines()
@@ -4566,7 +4561,7 @@ fn resume_directory_path_returns_typed_kind_and_hint_787() {
         !output.status.success(),
         "resume with directory should fail"
     );
-    let _stderr = String::from_utf8_lossy(&output.stderr);
+    let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let j: serde_json::Value = stdout
         .lines()
@@ -4616,7 +4611,7 @@ fn skills_show_not_found_emits_single_json_object_788() {
     assert!(!output.status.success(), "skills show unknown should fail");
     // Skills handler emits JSON to stdout; the duplicate was on stderr from the main error path.
     // After fix: stdout has 1 JSON object, stderr has none (no duplicate).
-    let _stdout = String::from_utf8_lossy(&output.stdout);
+    let stdout = String::from_utf8_lossy(&output.stdout);
     let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
 
@@ -4778,7 +4773,7 @@ fn system_prompt_unknown_option_returns_typed_kind_790() {
         &[],
     );
     assert!(!out1.status.success());
-    let _stderr1 = String::from_utf8_lossy(&out1.stderr);
+    let stderr1 = String::from_utf8_lossy(&out1.stderr);
     let stdout1 = String::from_utf8_lossy(&out1.stdout);
     let j1: serde_json::Value = stdout1
         .lines()
@@ -4805,7 +4800,7 @@ fn system_prompt_unknown_option_returns_typed_kind_790() {
         &[],
     );
     assert!(!out2.status.success());
-    let _stderr2 = String::from_utf8_lossy(&out2.stderr);
+    let stderr2 = String::from_utf8_lossy(&out2.stderr);
     let stdout2 = String::from_utf8_lossy(&out2.stdout);
     let j2: serde_json::Value = stdout2
         .lines()
@@ -4843,7 +4838,7 @@ fn config_extra_args_have_non_null_hint_791() {
         &[],
     );
     assert!(!out1.status.success());
-    let _stderr1 = String::from_utf8_lossy(&out1.stderr);
+    let stderr1 = String::from_utf8_lossy(&out1.stderr);
     let stdout1 = String::from_utf8_lossy(&out1.stdout);
     let j1: serde_json::Value = stdout1
         .lines()
@@ -4877,7 +4872,7 @@ fn config_extra_args_have_non_null_hint_791() {
         &[],
     );
     assert!(!out2.status.success());
-    let _stderr2 = String::from_utf8_lossy(&out2.stderr);
+    let stderr2 = String::from_utf8_lossy(&out2.stderr);
     let stdout2 = String::from_utf8_lossy(&out2.stdout);
     let j2: serde_json::Value = stdout2
         .lines()
@@ -5063,7 +5058,7 @@ fn plugins_uninstall_not_found_has_hint_793() {
         "plugins uninstall not-found must exit non-zero (#793)"
     );
     // Error envelope goes to stderr (propagated via ? to main error handler)
-    let _stderr = String::from_utf8_lossy(&output.stderr);
+    let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let j: serde_json::Value = stdout
         .lines()
@@ -5108,7 +5103,7 @@ fn plugins_install_not_found_path_returns_typed_kind_794() {
         !output.status.success(),
         "plugins install not-found-path must exit non-zero (#794)"
     );
-    let _stderr = String::from_utf8_lossy(&output.stderr);
+    let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let j: serde_json::Value = stdout
         .lines()
@@ -5372,7 +5367,7 @@ fn agents_create_scaffolds_toml_and_lists_locally_431() {
         .iter()
         .any(|agent| {
             agent["name"] == "my-agent"
-                && Path::new(agent["path"].as_str().expect("listed agent path"))
+                && PathBuf::from(agent["path"].as_str().expect("listed agent path"))
                     == fs::canonicalize(&agent_path).expect("canonical listed agent path")
         }));
 }
@@ -5497,7 +5492,7 @@ fn plugins_extra_args_have_non_null_hint_797() {
         !output.status.success(),
         "plugins show with extra arg must exit non-zero (#797)"
     );
-    let _stderr = String::from_utf8_lossy(&output.stderr);
+    let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let j: serde_json::Value = stdout
         .lines()
@@ -5563,7 +5558,7 @@ fn plugins_list_trailing_dash_text_error_stays_on_stderr_817() {
         String::from_utf8_lossy(&output.stdout)
     );
     let stderr = String::from_utf8_lossy(&output.stderr);
-    let _stdout = String::from_utf8_lossy(&output.stdout);
+    let stdout = String::from_utf8_lossy(&output.stdout);
     assert!(stderr.contains("[error-kind: cli_parse]"), "{stderr}");
     assert!(
         stderr.contains("unknown option for `claw plugins list`: --"),
@@ -5588,7 +5583,7 @@ fn empty_prompt_has_non_null_hint_798() {
         !output.status.success(),
         "empty prompt must exit non-zero (#798)"
     );
-    let _stderr = String::from_utf8_lossy(&output.stderr);
+    let stderr = String::from_utf8_lossy(&output.stderr);
     let stdout = String::from_utf8_lossy(&output.stdout);
     let j: serde_json::Value = stdout
         .lines()
diff --git a/rust/crates/tools/src/lib.rs b/rust/crates/tools/src/lib.rs
index e39efd21..2ad7926a 100644
--- a/rust/crates/tools/src/lib.rs
+++ b/rust/crates/tools/src/lib.rs
@@ -506,17 +506,13 @@ pub fn mvp_tool_specs() -> Vec<ToolSpec> {
         },
         ToolSpec {
             name: "read_file",
-            description: "Read a text file from the workspace. Large files come back one page at \
-                          a time: if the response has \"truncated\": true you have NOT seen the \
-                          whole file, and \"nextOffset\" is the line to pass as `offset` to \
-                          continue. Prefer grep_search to locate what you need over paging \
-                          through a big file, and never re-read a page you already have.",
+            description: "Read a text file from the workspace.",
             input_schema: json!({
                 "type": "object",
                 "properties": {
                     "path": { "type": "string" },
-                    "offset": { "type": "integer", "minimum": 0, "description": "First line to read (0-based). Pass the previous response's nextOffset to continue." },
-                    "limit": { "type": "integer", "minimum": 1, "description": "Maximum lines to return. Capped by a byte ceiling regardless." }
+                    "offset": { "type": "integer", "minimum": 0 },
+                    "limit": { "type": "integer", "minimum": 1 }
                 },
                 "required": ["path"],
                 "additionalProperties": false
@@ -10405,12 +10401,6 @@ mod tests {
 
     #[test]
     fn repl_executes_python_code() {
-        // Resolving the python runtime reads PATH, and PATH is process-global: the PowerShell
-        // tests below blank it while they run. Without this guard that races and this test
-        // intermittently fails with "python runtime not found" on a machine that has python.
-        let _guard = env_lock()
-            .lock()
-            .unwrap_or_else(std::sync::PoisonError::into_inner);
         let result = execute_tool(
             "REPL",
             &json!({"language": "python", "code": "print(1 + 1)", "timeout_ms": 500}),