fix: bound event stream refresh latency (#58)

src/main.py

@@ -14,6 +14,7 @@ from src.views import router as frontend_router
 
 app = FastAPI(title="Stackchain Dashboard")
 CONTEXT_TIMEOUT_SECONDS = 5.0
+EVENT_STREAM_TIMEOUT_SECONDS = 5.0
 FRONTEND_DIR = Path(__file__).resolve().parent.parent / "frontend"
 
 app.add_middleware(
@@ -103,5 +104,23 @@ async def context() -> JSONResponse:
 
 
 @app.get("/api/v1/events")
-async def event_stream() -> list[dict]:
-    return await activity_events()
+async def event_stream():
+    try:
+        return await asyncio.wait_for(
+            activity_events(), timeout=EVENT_STREAM_TIMEOUT_SECONDS
+        )
+    except TimeoutError:
+        return JSONResponse(
+            {
+                "error": (
+                    "Gitea event stream request timed out after "
+                    f"{EVENT_STREAM_TIMEOUT_SECONDS:g}s"
+                )
+            },
+            status_code=503,
+            headers={
+                "Retry-After": str(
+                    max(1, math.ceil(EVENT_STREAM_TIMEOUT_SECONDS))
+                )
+            },
+        )