fix: mcp_health capabilities KeyError; verify DATABASE_URL in init_db_pool

app_part1.py

@@ -89,7 +89,7 @@ async def lifespan(app: FastAPI):
     global db_pool
     try:
         db_pool = await init_db_pool()
-        logger.info("Database pool initialized.")
+        logger.info("Database pool initialized — postgres_connected=True")
     except Exception as exc:
         logger.error(
             "Failed to initialize Postgres pool. Falling back to memory: %s",

mcp_routes.py

@@ -538,7 +538,7 @@ async def mcp_health() -> JSONResponse:
     live_servers = _servers_with_live_health()
     seen: List[str] = []
     for server in live_servers:
-        for cap in server["capabilities"]:
+        for cap in server.get("capabilities", []):
             if cap not in seen:
                 seen.append(cap)
     overall = "healthy" if all(s["health_status"] == "healthy" for s in live_servers) else "degraded"