fix: bound readiness probe latency (#71)

src/main.py

@@ -15,6 +15,7 @@ from src.views import router as frontend_router
 app = FastAPI(title="Stackchain Dashboard")
 CONTEXT_TIMEOUT_SECONDS = 5.0
 EVENT_STREAM_TIMEOUT_SECONDS = 5.0
+READINESS_TIMEOUT_SECONDS = 5.0
 FRONTEND_DIR = Path(__file__).resolve().parent.parent / "frontend"
 
 app.add_middleware(
@@ -39,15 +40,26 @@ def health() -> dict[str, str]:
 async def readiness():
     """Return readiness after verifying the configured Gitea connection."""
     try:
-        user = await current_user()
+        user = await asyncio.wait_for(
+            current_user(), timeout=READINESS_TIMEOUT_SECONDS
+        )
     except Exception as exc:
+        timed_out = isinstance(exc, TimeoutError)
+        error_message = (
+            f"Gitea readiness check timed out after {READINESS_TIMEOUT_SECONDS:g}s"
+            if timed_out
+            else str(exc)
+        )
         return JSONResponse(
             {
                 "status": "not_ready",
                 "service": "stackchain-dashboard",
-                "error": str(exc),
+                "error": error_message,
             },
             status_code=503,
+            headers={
+                "Retry-After": str(max(1, math.ceil(READINESS_TIMEOUT_SECONDS)))
+            } if timed_out else None,
         )
     return {
         "status": "ready",