feat(feedback): add PUT upsert and DELETE-by-run endpoints

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/gateway/routers/feedback.py

@@ -30,6 +30,11 @@ class FeedbackCreateRequest(BaseModel):
     message_id: str | None = Field(default=None, description="Optional: scope feedback to a specific message")
 
 
+class FeedbackUpsertRequest(BaseModel):
+    rating: int = Field(..., description="Feedback rating: +1 (positive) or -1 (negative)")
+    comment: str | None = Field(default=None, description="Optional text feedback")
+
+
 class FeedbackResponse(BaseModel):
     feedback_id: str
     run_id: str
@@ -53,6 +58,57 @@ class FeedbackStatsResponse(BaseModel):
 # ---------------------------------------------------------------------------
 
 
+@router.put("/{thread_id}/runs/{run_id}/feedback", response_model=FeedbackResponse)
+@require_permission("threads", "write", owner_check=True, require_existing=True)
+async def upsert_feedback(
+    thread_id: str,
+    run_id: str,
+    body: FeedbackUpsertRequest,
+    request: Request,
+) -> dict[str, Any]:
+    """Create or update feedback for a run (idempotent)."""
+    if body.rating not in (1, -1):
+        raise HTTPException(status_code=400, detail="rating must be +1 or -1")
+
+    user_id = await get_current_user(request)
+
+    run_store = get_run_store(request)
+    run = await run_store.get(run_id)
+    if run is None:
+        raise HTTPException(status_code=404, detail=f"Run {run_id} not found")
+    if run.get("thread_id") != thread_id:
+        raise HTTPException(status_code=404, detail=f"Run {run_id} not found in thread {thread_id}")
+
+    feedback_repo = get_feedback_repo(request)
+    return await feedback_repo.upsert(
+        run_id=run_id,
+        thread_id=thread_id,
+        rating=body.rating,
+        user_id=user_id,
+        comment=body.comment,
+    )
+
+
+@router.delete("/{thread_id}/runs/{run_id}/feedback")
+@require_permission("threads", "delete", owner_check=True, require_existing=True)
+async def delete_run_feedback(
+    thread_id: str,
+    run_id: str,
+    request: Request,
+) -> dict[str, bool]:
+    """Delete the current user's feedback for a run."""
+    user_id = await get_current_user(request)
+    feedback_repo = get_feedback_repo(request)
+    deleted = await feedback_repo.delete_by_run(
+        thread_id=thread_id,
+        run_id=run_id,
+        user_id=user_id,
+    )
+    if not deleted:
+        raise HTTPException(status_code=404, detail="No feedback found for this run")
+    return {"success": True}
+
+
 @router.post("/{thread_id}/runs/{run_id}/feedback", response_model=FeedbackResponse)
 @require_permission("threads", "write", owner_check=True, require_existing=True)
 async def create_feedback(