feat(webhook): dedup deliveries by delivery_id (M-7)

src/webhooks/gitea.py

@@ -10,7 +10,14 @@ import httpx
 from fastapi import APIRouter, Request, HTTPException
 
 from ..config import settings
-from ..db import get_db, get_task_by_repo_branch, update_task_stage, enqueue_job
+from ..db import (
+    get_db,
+    get_task_by_repo_branch,
+    update_task_stage,
+    enqueue_job,
+    insert_event_dedup,
+)
+from ._dedup import gitea_delivery_id
 from ..stages import get_next_stage, get_agent_for_stage
 from ..qg.checks import check_ci_green, check_review_approved
 from ..notifications import notify_stage_change, notify_qg_failure, notify_error
@@ -51,15 +58,17 @@ async def gitea_webhook(request: Request):
 
     payload = json.loads(body)
 
-    # Log event
-    conn = get_db()
+    # ORCH-5 (M-7): idempotent logging. Compute a stable delivery_id (X-Gitea-Delivery
+    # GUID, or sha256 fallback) and INSERT OR IGNORE. A repeated delivery (Gitea retry
+    # / manual replay) returns inserted=False -> log + return {"status":"duplicate"}
+    # WITHOUT re-dispatching, so the pipeline is not re-triggered (ET-009 class).
+    # Runs AFTER HMAC verification above.
     event_type = request.headers.get("X-Gitea-Event", "unknown")
-    conn.execute(
-        "INSERT INTO events (source, event_type, payload) VALUES (?, ?, ?)",
-        ("gitea", event_type, body.decode()),
-    )
-    conn.commit()
-    conn.close()
+    delivery_id = gitea_delivery_id(request.headers, event_type, body)
+    inserted = insert_event_dedup("gitea", event_type, body.decode(), delivery_id)
+    if not inserted:
+        logger.info(f"Gitea webhook duplicate delivery_id={delivery_id}, skipping dispatch")
+        return {"status": "duplicate"}
 
     if event_type == "push":
         await handle_push(payload)