fix(api): restore Alertmanager project context

apps/api/src/main.py

@@ -120,6 +120,26 @@ from src.workers import close_signal_worker, init_signal_worker
 setup_logging()
 logger = get_logger("awoooi.api")
 
+ALERTMANAGER_WEBHOOK_PATH = "/api/v1/webhooks/alertmanager"
+ALERTMANAGER_DEFAULT_PROJECT_ID = "awoooi"
+
+
+def _resolve_request_project_context(request: Request) -> tuple[str | None, str]:
+    """Resolve tenant context for RLS while keeping non-webhook routes fail-closed."""
+    for candidate in (
+        request.headers.get("X-Project-ID"),
+        request.headers.get("X-Tenant-ID"),
+        request.query_params.get("project_id"),
+    ):
+        project_id = candidate.strip() if candidate else None
+        if project_id:
+            return project_id, "request.header_or_query"
+
+    if request.url.path == ALERTMANAGER_WEBHOOK_PATH:
+        return ALERTMANAGER_DEFAULT_PROJECT_ID, "request.alertmanager.default_project"
+
+    return None, "request.project_id.missing"
+
 # =============================================================================
 # Sentry SDK Initialization (Error Tracking - 補強 SignOz)
 # Self-Hosted @ 192.168.0.110
@@ -905,15 +925,7 @@ async def request_logging_middleware(request: Request, call_next):
     from src.core.context import clear_project_context, get_current_project_context, set_project_context
 
     request_id = request.headers.get("X-Request-ID") or str(uuid4())
-    project_id = (
-        request.headers.get("X-Project-ID")
-        or request.headers.get("X-Tenant-ID")
-        or request.query_params.get("project_id")
-    )
-    project_id = project_id.strip() if project_id else None
-    source = "request.project_id.missing"
-    if project_id:
-        source = "request.header_or_query"
+    project_id, source = _resolve_request_project_context(request)
 
     context_tokens = set_project_context(
         project_id=project_id,