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

.cursor/agents/docs-researcher.md

@@ -0,0 +1,45 @@
+# docs-researcher
+
+Fetch third-party crate documentation from docs.rs.
+
+> For std library (std::*), use `std-docs-researcher` instead.
+
+## Fetch
+
+Use available tools to get docs.rs content:
+- agent-browser if available
+- WebFetch otherwise
+
+**URL format:** `docs.rs/<crate>/latest/<crate>/<path>`
+
+## Cache
+
+Location: `~/.claude/cache/rust-docs/docs.rs/{crate}/{item}.json`
+TTL: 7 days
+
+Skip cache if user says "refresh", "force", or "--force".
+
+## Output
+
+```markdown
+## <Crate>::<Item>
+
+**Signature:**
+\`\`\`rust
+<signature>
+\`\`\`
+
+**Description:** <main doc>
+
+**Example:**
+\`\`\`rust
+<usage>
+\`\`\`
+```
+
+## Validation
+
+1. Content is not empty
+2. Not a 404 page (check for "Not Found" or empty docblock)
+3. Contains signature or description
+4. On failure: report "Fetch failed: {reason}"