fix(telegram): async webhook handler + deduplicate callback responses

- Webhook returns 200 immediately, processing runs in background task
  → Telegram no longer retries, eliminates duplicate callbacks and 400 errors
- Consolidate answer_callback_query call to top of handler (before heavy work)
- Add logger.info/error for callback actions to aid debugging

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

backend/app/main.py

@@ -677,7 +677,14 @@ def api_n8n_ingest(request: Request) -> dict:
 
 @app.post("/telegram/webhook")
 async def telegram_webhook(request: Request) -> dict:
-    """Receive updates from Telegram Bot API."""
+    """Receive updates from Telegram Bot API.
+
+    Returns 200 immediately so Telegram never retries the same update.
+    Actual processing runs in a background task.
+    """
+    import asyncio
+    import logging
+
     # Verify secret token
     secret = settings.telegram_webhook_secret
     if secret:
@@ -691,12 +698,14 @@ async def telegram_webhook(request: Request) -> dict:
     except Exception:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Invalid JSON")
 
-    try:
-        handle_update(update)
-    except Exception as exc:
-        import logging
-        logging.getLogger(__name__).error("Telegram update handler error: %s", exc)
+    async def _process():
+        loop = asyncio.get_event_loop()
+        try:
+            await loop.run_in_executor(None, lambda: handle_update(update))
+        except Exception as exc:
+            logging.getLogger(__name__).error("Telegram update handler error: %s", exc)
 
+    asyncio.create_task(_process())
     return {"ok": True}
 
 

backend/app/telegram_bot.py

@@ -400,9 +400,19 @@ def _handle_callback(callback_query: dict[str, Any]) -> None:
         answer_callback_query(query_id, "Artikel nicht gefunden")
         return
 
+    # Answer Telegram immediately so the spinning indicator stops
+    action_labels = {
+        "rewrite": "✏️ Artikel wird neu geschrieben …",
+        "discard": "❌ Artikel verworfen",
+        "override": "➕ Artikel wird verarbeitet …",
+        "reject": "🚫 Abgelehnt",
+    }
+    answer_callback_query(query_id, action_labels.get(action, ""))
+    edit_message_reply_markup(chat_id, message_id)
+
+    logger.info("Callback: action=%s article_id=%s", action, article_id)
+
     if action == "rewrite":
-        answer_callback_query(query_id, "✏️ Artikel wird neu geschrieben …")
-        edit_message_reply_markup(chat_id, message_id)
         try:
             _pipeline.rewrite_and_update_draft(article_id)
             updated = get_article_by_id(article_id)
@@ -411,28 +421,25 @@ def _handle_callback(callback_query: dict[str, Any]) -> None:
                 slot = suggest_publish_slot()
                 notify_new_draft(updated, score=_get_relevance_score(updated), suggested_publish_at=slot)
         except Exception as exc:
+            logger.error("Rewrite #%d fehlgeschlagen: %s", article_id, exc)
             notify_error(f"Rewrite #{article_id} fehlgeschlagen: {exc}")
 
     elif action == "discard":
-        answer_callback_query(query_id, "❌ Artikel verworfen")
-        edit_message_reply_markup(chat_id, message_id)
         try:
             _pipeline.discard_article(article_id)
         except Exception as exc:
+            logger.error("Discard #%d fehlgeschlagen: %s", article_id, exc)
             notify_error(f"Verwerfen #{article_id} fehlgeschlagen: {exc}")
 
     elif action == "override":
-        answer_callback_query(query_id, "➕ Artikel wird verarbeitet …")
-        edit_message_reply_markup(chat_id, message_id)
         try:
             _pipeline.override_rejected_article(article_id)
         except Exception as exc:
+            logger.error("Override #%d fehlgeschlagen: %s", article_id, exc)
             notify_error(f"Override #{article_id} fehlgeschlagen: {exc}")
 
     elif action == "reject":
-        answer_callback_query(query_id, "🚫 Abgelehnt")
-        edit_message_reply_markup(chat_id, message_id)
         update_article_status(article_id, "error", actor="telegram", note="Manuell abgelehnt via Telegram")
 
     else:
-        answer_callback_query(query_id, "Unbekannte Aktion")
+        logger.warning("Unbekannte Callback-Aktion: %s", action)