Claude Code: Fix missing Path import causing app.py startup failure

The Path class from pathlib was used but not imported, causing a
NameError at module load time that prevented FastAPI app initialization.
This broke A2A communication since the /a2a/jsonrpc endpoint was never
registered.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app.py

@@ -21,6 +21,7 @@ if 'CAIN_STATUS_PATH' not in os.environ and 'OPENCLAW_DATA_DIR' in os.environ:
 
 # CRITICAL: Create FastAPI app at TOP LEVEL, outside any try/except
 # This ensures the server ALWAYS starts, even if brain is broken
+from pathlib import Path
 from fastapi import FastAPI, Request
 from fastapi.responses import JSONResponse, FileResponse
 from fastapi.staticfiles import StaticFiles