feat(rust): surface workspace skill discovery in /skills

The TypeScript CLI exposes a skills browser backed by workspace/user skill
discovery, while the Rust port only had partial local loading and an
inconsistent slash-command view. This change adds a shared runtime skill
discovery path, teaches the Skill tool to resolve workspace `.codex/.claw`
skills plus legacy `/commands`, and makes `/skills` report the checked local
skill directories in the current workspace context.

Constraint: Keep scope limited to local/workspace skill discovery without inventing bundled or remote registries yet
Rejected: Add a bundled skill registry surface now | too broad for this parity increment
Rejected: Leave tool resolution and /skills discovery separate | misleading output and weaker parity with TS
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Extend the shared runtime skill discovery path before adding new skill sources so the tool surface and /skills stay aligned
Tested: cargo fmt --all; cargo test -p runtime skills:: -- --nocapture; cargo test -p commands skills -- --nocapture; cargo test -p tools skill_ -- --nocapture; cargo test -p claw-cli skills -- --nocapture; cargo test -p claw-cli init_help_mentions_direct_subcommand -- --nocapture
Not-tested: Full workspace-wide cargo test sweep

rust/crates/runtime/src/lib.rs

@@ -15,12 +15,9 @@ mod prompt;
 mod remote;
 pub mod sandbox;
 mod session;
+mod skills;
 mod usage;
 
-pub use lsp::{
-    FileDiagnostics, LspContextEnrichment, LspError, LspManager, LspServerConfig,
-    SymbolLocation, WorkspaceDiagnostics,
-};
 pub use bash::{execute_bash, BashCommandInput, BashCommandOutput};
 pub use bootstrap::{BootstrapPhase, BootstrapPlan};
 pub use compact::{
@@ -28,8 +25,8 @@ pub use compact::{
     get_compact_continuation_message, should_compact, CompactionConfig, CompactionResult,
 };
 pub use config::{
-    ConfigEntry, ConfigError, ConfigLoader, ConfigSource, McpManagedProxyServerConfig,
-    McpConfigCollection, McpOAuthConfig, McpRemoteServerConfig, McpSdkServerConfig,
+    ConfigEntry, ConfigError, ConfigLoader, ConfigSource, McpConfigCollection,
+    McpManagedProxyServerConfig, McpOAuthConfig, McpRemoteServerConfig, McpSdkServerConfig,
     McpServerConfig, McpStdioServerConfig, McpTransport, McpWebSocketServerConfig, OAuthConfig,
     ResolvedPermissionMode, RuntimeConfig, RuntimeFeatureConfig, RuntimeHookConfig,
     RuntimePluginConfig, ScopedMcpServerConfig, CLAW_SETTINGS_SCHEMA_NAME,
@@ -44,12 +41,16 @@ pub use file_ops::{
     WriteFileOutput,
 };
 pub use hooks::{HookEvent, HookRunResult, HookRunner};
+pub use lsp::{
+    FileDiagnostics, LspContextEnrichment, LspError, LspManager, LspServerConfig, SymbolLocation,
+    WorkspaceDiagnostics,
+};
 pub use mcp::{
     mcp_server_signature, mcp_tool_name, mcp_tool_prefix, normalize_name_for_mcp,
     scoped_mcp_config_hash, unwrap_ccr_proxy_url,
 };
 pub use mcp_client::{
-    McpManagedProxyTransport, McpClientAuth, McpClientBootstrap, McpClientTransport,
+    McpClientAuth, McpClientBootstrap, McpClientTransport, McpManagedProxyTransport,
     McpRemoteTransport, McpSdkTransport, McpStdioTransport,
 };
 pub use mcp_stdio::{
@@ -81,6 +82,10 @@ pub use remote::{
     DEFAULT_SESSION_TOKEN_PATH, DEFAULT_SYSTEM_CA_BUNDLE, NO_PROXY_HOSTS, UPSTREAM_PROXY_ENV_KEYS,
 };
 pub use session::{ContentBlock, ConversationMessage, MessageRole, Session, SessionError};
+pub use skills::{
+    discover_skill_roots, resolve_skill_path, SkillDiscoveryRoot, SkillDiscoverySource,
+    SkillRootKind,
+};
 pub use usage::{
     format_usd, pricing_for_model, ModelPricing, TokenUsage, UsageCostEstimate, UsageTracker,
 };

rust/crates/runtime/src/skills.rs

@@ -0,0 +1,313 @@
+use std::env;
+use std::path::{Path, PathBuf};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub enum SkillDiscoverySource {
+    ProjectCodex,
+    ProjectClaw,
+    UserCodexHome,
+    UserCodex,
+    UserClaw,
+}
+
+impl SkillDiscoverySource {
+    #[must_use]
+    pub const fn label(self) -> &'static str {
+        match self {
+            Self::ProjectCodex => "Project (.codex)",
+            Self::ProjectClaw => "Project (.claw)",
+            Self::UserCodexHome => "User ($CODEX_HOME)",
+            Self::UserCodex => "User (~/.codex)",
+            Self::UserClaw => "User (~/.claw)",
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum SkillRootKind {
+    SkillsDir,
+    LegacyCommandsDir,
+}
+
+impl SkillRootKind {
+    #[must_use]
+    pub const fn detail_label(self) -> Option<&'static str> {
+        match self {
+            Self::SkillsDir => None,
+            Self::LegacyCommandsDir => Some("legacy /commands"),
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct SkillDiscoveryRoot {
+    pub source: SkillDiscoverySource,
+    pub path: PathBuf,
+    pub kind: SkillRootKind,
+}
+
+pub fn discover_skill_roots(cwd: &Path) -> Vec<SkillDiscoveryRoot> {
+    let mut roots = Vec::new();
+
+    for ancestor in cwd.ancestors() {
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::ProjectCodex,
+            ancestor.join(".codex").join("skills"),
+            SkillRootKind::SkillsDir,
+        );
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::ProjectClaw,
+            ancestor.join(".claw").join("skills"),
+            SkillRootKind::SkillsDir,
+        );
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::ProjectCodex,
+            ancestor.join(".codex").join("commands"),
+            SkillRootKind::LegacyCommandsDir,
+        );
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::ProjectClaw,
+            ancestor.join(".claw").join("commands"),
+            SkillRootKind::LegacyCommandsDir,
+        );
+    }
+
+    if let Ok(codex_home) = env::var("CODEX_HOME") {
+        let codex_home = PathBuf::from(codex_home);
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::UserCodexHome,
+            codex_home.join("skills"),
+            SkillRootKind::SkillsDir,
+        );
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::UserCodexHome,
+            codex_home.join("commands"),
+            SkillRootKind::LegacyCommandsDir,
+        );
+    }
+
+    if let Some(home) = env::var_os("HOME") {
+        let home = PathBuf::from(home);
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::UserCodex,
+            home.join(".codex").join("skills"),
+            SkillRootKind::SkillsDir,
+        );
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::UserCodex,
+            home.join(".codex").join("commands"),
+            SkillRootKind::LegacyCommandsDir,
+        );
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::UserClaw,
+            home.join(".claw").join("skills"),
+            SkillRootKind::SkillsDir,
+        );
+        push_unique_skill_root(
+            &mut roots,
+            SkillDiscoverySource::UserClaw,
+            home.join(".claw").join("commands"),
+            SkillRootKind::LegacyCommandsDir,
+        );
+    }
+
+    roots
+}
+
+pub fn resolve_skill_path(skill: &str, cwd: &Path) -> Result<PathBuf, String> {
+    let requested = normalize_requested_skill_name(skill)?;
+
+    for root in discover_skill_roots(cwd) {
+        match root.kind {
+            SkillRootKind::SkillsDir => {
+                let direct = root.path.join(&requested).join("SKILL.md");
+                if direct.is_file() {
+                    return Ok(direct);
+                }
+
+                if let Ok(entries) = std::fs::read_dir(&root.path) {
+                    for entry in entries.flatten() {
+                        let path = entry.path().join("SKILL.md");
+                        if !path.is_file() {
+                            continue;
+                        }
+                        if entry
+                            .file_name()
+                            .to_string_lossy()
+                            .eq_ignore_ascii_case(&requested)
+                        {
+                            return Ok(path);
+                        }
+                    }
+                }
+            }
+            SkillRootKind::LegacyCommandsDir => {
+                let direct_markdown = root.path.join(format!("{requested}.md"));
+                if direct_markdown.is_file() {
+                    return Ok(direct_markdown);
+                }
+
+                let direct_skill_dir = root.path.join(&requested).join("SKILL.md");
+                if direct_skill_dir.is_file() {
+                    return Ok(direct_skill_dir);
+                }
+
+                if let Ok(entries) = std::fs::read_dir(&root.path) {
+                    for entry in entries.flatten() {
+                        let path = entry.path();
+                        if path.is_dir() {
+                            let skill_path = path.join("SKILL.md");
+                            if !skill_path.is_file() {
+                                continue;
+                            }
+                            if entry
+                                .file_name()
+                                .to_string_lossy()
+                                .eq_ignore_ascii_case(&requested)
+                            {
+                                return Ok(skill_path);
+                            }
+                            continue;
+                        }
+
+                        if !path
+                            .extension()
+                            .is_some_and(|ext| ext.to_string_lossy().eq_ignore_ascii_case("md"))
+                        {
+                            continue;
+                        }
+
+                        let Some(stem) = path.file_stem() else {
+                            continue;
+                        };
+                        if stem.to_string_lossy().eq_ignore_ascii_case(&requested) {
+                            return Ok(path);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    Err(format!("unknown skill: {requested}"))
+}
+
+fn normalize_requested_skill_name(skill: &str) -> Result<String, String> {
+    let requested = skill.trim().trim_start_matches('/').trim_start_matches('$');
+    if requested.is_empty() {
+        return Err(String::from("skill must not be empty"));
+    }
+    Ok(requested.to_string())
+}
+
+fn push_unique_skill_root(
+    roots: &mut Vec<SkillDiscoveryRoot>,
+    source: SkillDiscoverySource,
+    path: PathBuf,
+    kind: SkillRootKind,
+) {
+    if path.is_dir() && !roots.iter().any(|existing| existing.path == path) {
+        roots.push(SkillDiscoveryRoot { source, path, kind });
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::fs;
+    use std::path::{Path, PathBuf};
+    use std::time::{SystemTime, UNIX_EPOCH};
+
+    use super::{
+        discover_skill_roots, resolve_skill_path, SkillDiscoveryRoot, SkillDiscoverySource,
+        SkillRootKind,
+    };
+
+    fn temp_dir(label: &str) -> PathBuf {
+        let nanos = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .expect("clock")
+            .as_nanos();
+        std::env::temp_dir().join(format!("runtime-skills-{label}-{nanos}"))
+    }
+
+    fn write_skill(root: &Path, name: &str) {
+        let skill_root = root.join(name);
+        fs::create_dir_all(&skill_root).expect("skill root");
+        fs::write(skill_root.join("SKILL.md"), format!("# {name}\n")).expect("write skill");
+    }
+
+    fn write_legacy_markdown(root: &Path, name: &str) {
+        fs::create_dir_all(root).expect("legacy root");
+        fs::write(root.join(format!("{name}.md")), format!("# {name}\n")).expect("write command");
+    }
+
+    #[test]
+    fn discovers_workspace_and_user_skill_roots() {
+        let _guard = crate::test_env_lock();
+        let workspace = temp_dir("workspace");
+        let nested = workspace.join("apps").join("ui");
+        let user_home = temp_dir("home");
+
+        fs::create_dir_all(&nested).expect("nested cwd");
+        fs::create_dir_all(workspace.join(".codex").join("skills")).expect("project codex skills");
+        fs::create_dir_all(workspace.join(".claw").join("commands"))
+            .expect("project claw commands");
+        fs::create_dir_all(user_home.join(".codex").join("skills")).expect("user codex skills");
+
+        std::env::set_var("HOME", &user_home);
+        std::env::remove_var("CODEX_HOME");
+
+        let roots = discover_skill_roots(&nested);
+
+        assert!(roots.contains(&SkillDiscoveryRoot {
+            source: SkillDiscoverySource::ProjectCodex,
+            path: workspace.join(".codex").join("skills"),
+            kind: SkillRootKind::SkillsDir,
+        }));
+        assert!(roots.contains(&SkillDiscoveryRoot {
+            source: SkillDiscoverySource::ProjectClaw,
+            path: workspace.join(".claw").join("commands"),
+            kind: SkillRootKind::LegacyCommandsDir,
+        }));
+        assert!(roots.contains(&SkillDiscoveryRoot {
+            source: SkillDiscoverySource::UserCodex,
+            path: user_home.join(".codex").join("skills"),
+            kind: SkillRootKind::SkillsDir,
+        }));
+
+        std::env::remove_var("HOME");
+        let _ = fs::remove_dir_all(workspace);
+        let _ = fs::remove_dir_all(user_home);
+    }
+
+    #[test]
+    fn resolves_workspace_skills_and_legacy_commands() {
+        let _guard = crate::test_env_lock();
+        let workspace = temp_dir("resolve");
+        let nested = workspace.join("apps").join("ui");
+        let original_dir = std::env::current_dir().expect("cwd");
+
+        fs::create_dir_all(&nested).expect("nested cwd");
+        write_skill(&workspace.join(".claw").join("skills"), "review");
+        write_legacy_markdown(&workspace.join(".codex").join("commands"), "deploy");
+
+        std::env::set_current_dir(&nested).expect("set cwd");
+        let review = resolve_skill_path("review", &nested).expect("workspace skill");
+        let deploy = resolve_skill_path("/deploy", &nested).expect("legacy command");
+        std::env::set_current_dir(&original_dir).expect("restore cwd");
+
+        assert!(review.ends_with(".claw/skills/review/SKILL.md"));
+        assert!(deploy.ends_with(".codex/commands/deploy.md"));
+
+        let _ = fs::remove_dir_all(workspace);
+    }
+}