Make repeated provider crashes self-identifying after retry exhaustion

Generic fatal wrapper handling already preserved safe classes and trace ids for single provider failures, but repeated retry exhaustion still surfaced as provider_internal. Classify generic wrapped RetriesExhausted failures as provider_retry_exhausted so Jobdori-style repeat failures stay distinguishable from one-off provider crashes, and keep the display logic clippy-clean.

Constraint: Keep the change minimal and preserve existing user-visible error wording outside retry-exhaustion classification
Rejected: Broadly rework all provider error taxonomy | unnecessary for the targeted opaque-wrapper regression
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Keep retry exhaustion distinct from single-shot provider_internal wrappers when the nested error is the same generic fatal wrapper
Tested: cargo test -p api detects_generic_fatal_wrapper_and_classifies_it_as_provider_internal
Tested: cargo test -p api retries_exhausted_preserves_nested_request_id_and_failure_class
Tested: cargo test -p rusty-claude-cli opaque_provider_wrapper_surfaces_failure_class_session_and_trace
Tested: cargo test -p rusty-claude-cli retry_exhaustion_uses_retry_failure_class_for_generic_provider_wrapper
Tested: cargo test --workspace
Tested: cargo fmt --check
Tested: cargo clippy --workspace --all-targets -- -D warnings
Not-tested: Live OpenClaw/Anthropic service failure telemetry outside the local test harness

rust/crates/api/src/error.rs

@@ -103,7 +103,11 @@ impl ApiError {
     #[must_use]
     pub fn safe_failure_class(&self) -> &'static str {
         match self {
-            Self::RetriesExhausted { .. } => "provider_retry_exhausted",
+            Self::RetriesExhausted { .. } if self.is_context_window_failure() => "context_window",
+            Self::RetriesExhausted { .. } if self.is_generic_fatal_wrapper() => {
+                "provider_retry_exhausted"
+            }
+            Self::RetriesExhausted { last_error, .. } => last_error.safe_failure_class(),
             Self::MissingCredentials { .. } | Self::ExpiredOAuthToken | Self::Auth(_) => {
                 "provider_auth"
             }