fix(polling): httpx client timeout 改為分開設定，read=50s > getUpdates 40s

根因: httpx.AsyncClient(timeout=30.0) 的 read timeout 30s
     < getUpdates 的 long polling timeout 40s
     導致每次 getUpdates 都被 client 打斷 → polling loop 無法正常收訊息

修法: httpx.Timeout(connect=10s, read=50s) 讓 long polling 正常等待

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

apps/api/src/services/telegram_gateway.py

@@ -1085,8 +1085,11 @@ class TelegramGateway:
             logger.warning("telegram_gateway_disabled", reason="Chat ID not configured")
             return False
 
+        # 2026-04-03 ogt: timeout 改用 httpx.Timeout 分開設定
+        # connect=10s, read=50s (getUpdates long polling timeout 40s + buffer)
+        # 舊的 timeout=30.0 會讓 getUpdates(timeout=40s) 每次都被 client 先打斷
         self._http_client = httpx.AsyncClient(
-            timeout=30.0,
+            timeout=httpx.Timeout(connect=10.0, read=50.0, write=10.0, pool=10.0),
             headers={"Content-Type": "application/json"},
         )