This PR fixes three bugs that prevented the MCP plugin from working:
1. **Fixed parameter name mismatch in tools.py**
- Changed `workspace_root=workspace_root` to `working_dir=workspace_root`
- The `create_bd_client()` function expects `working_dir` parameter,
but tools.py was passing `workspace_root`
- This caused "got an unexpected keyword argument 'workspace_root'" error
2. **Added version check guard for daemon client**
- Added `hasattr(_client, '_check_version')` check before calling
- BdDaemonClient doesn't have `_check_version()` method, only BdCliClient does
- This caused "'BdDaemonClient' object has no attribute '_check_version'" error
3. **Implemented proper daemon socket detection for fallback**
- Added synchronous socket file existence check before creating daemon client
- Walks up directory tree looking for `.beads/bd.sock` file
- Only creates daemon client if socket exists, otherwise falls back to CLI
- Previously, daemon client was created but failed on first method call
- This enables the documented "prefer_daemon with automatic CLI fallback" behavior
**Testing:**
- Verified MCP tools work correctly with single-repo setup
- Confirmed automatic fallback to CLI when daemon isn't running
- Tested on macOS with bd v0.9.9
**Related Issues:**
- Addresses symptoms similar to #65 (Windows BEADS_WORKING_DIR issue)
74b460b298