Normalize Telegram t.me channel IDs

gateway/app.py

@@ -45,13 +45,30 @@ def _error_alert_bot_token() -> str:
     return os.getenv("ERROR_TELEGRAM_ALERT_BOT_TOKEN", "").strip()
 
 
+def _normalize_telegram_chat_id(raw_id: str) -> str:
+    value = raw_id.strip()
+    if not value:
+        return value
+
+    lowered = value.lower()
+    for prefix in ("https://t.me/", "http://t.me/", "t.me/"):
+        if lowered.startswith(prefix):
+            value = value[len(prefix):].strip()
+            break
+
+    if not value.startswith(("@", "-100")) and not value.isdigit():
+        value = f"@{value}"
+    return value
+
+
 def _error_alert_chat_ids() -> list[str]:
     raw = os.getenv("ERROR_TELEGRAM_ALERT_CHAT_IDS", "").strip()
     if not raw:
         raw = os.getenv("ERROR_TELEGRAM_ALERT_CHANNEL_ID", "").strip()
         if not raw:
             raw = os.getenv("ERROR_TELEGRAM_ALERT_CHANNEL", "").strip()
-    return [item.strip() for item in raw.split(",") if item.strip()]
+    normalized = [_normalize_telegram_chat_id(item) for item in raw.split(",")]
+    return [item for item in normalized if item]
 
 
 def _error_alert_min_status() -> int: