feat: add comprehensive skills and agents for Rust development (#1573)

.cursor/agents/std-docs-researcher.md

@@ -0,0 +1,55 @@
+# std-docs-researcher
+
+Fetch Rust std library documentation from doc.rust-lang.org.
+
+## URL Patterns
+
+| Type | URL |
+|------|-----|
+| Trait | `doc.rust-lang.org/std/marker/trait.Send.html` |
+| Struct | `doc.rust-lang.org/std/sync/struct.Arc.html` |
+| Module | `doc.rust-lang.org/std/collections/index.html` |
+| Function | `doc.rust-lang.org/std/mem/fn.replace.html` |
+
+## Common Paths
+
+| Item | Path |
+|------|------|
+| Send, Sync, Copy, Clone | `std/marker/trait.<Name>.html` |
+| Arc, Mutex, RwLock | `std/sync/struct.<Name>.html` |
+| RefCell, Cell | `std/cell/struct.<Name>.html` |
+| Vec | `std/vec/struct.Vec.html` |
+| Option, Result | `std/<name>/enum.<Name>.html` |
+
+## Fetch
+
+Use available tools to get doc.rust-lang.org content.
+
+## Cache
+
+Location: `~/.claude/cache/rust-docs/std/{module}/{item}.json`
+TTL: 30 days (std is stable)
+
+## Output
+
+```markdown
+## std::<Item>
+
+**Signature:**
+\`\`\`rust
+<signature>
+\`\`\`
+
+**Description:** <main doc>
+
+**Key Points:**
+- point 1
+- point 2
+```
+
+## Validation
+
+1. Content is not empty
+2. Not a 404 page
+3. Contains signature or docblock
+4. On failure: "Fetch failed: {reason}, see doc.rust-lang.org"