feat(telegram): add 'none' listener mode for bots

Introduce a third update_mode option alongside polling/webhook. 'none'
disables both polling and webhook delivery — useful when another instance
owns the listener or when the bot is send-only. Switching into 'none' now
unschedules polling and unregisters any active webhook so Telegram stops
delivering updates.

New bots default to 'none' (safer when multiple bridges share a token).
Existing bots upgraded from a pre-update_mode schema keep 'polling' so
their behavior is unchanged.

packages/server/src/notify_bridge_server/api/telegram_bots.py

@@ -86,6 +86,11 @@ async def update_bot(
         bot.icon = body.icon
     # Handle mode switching
     if body.update_mode is not None and body.update_mode != bot.update_mode:
+        if body.update_mode not in ("none", "polling", "webhook"):
+            raise HTTPException(
+                status_code=400,
+                detail=f"Invalid update_mode: {body.update_mode!r}. Must be 'none', 'polling', or 'webhook'.",
+            )
         if body.update_mode == "webhook":
             # Validate and register webhook BEFORE stopping polling
             base_url = await get_setting(session, "external_url")
@@ -108,6 +113,12 @@ async def update_bot(
             # Switching to polling: unregister webhook, start polling
             await unregister_webhook(bot.token)
             schedule_bot_polling(bot.id)
+        elif body.update_mode == "none":
+            # Disable listener: stop polling and clear any webhook so Telegram
+            # stops delivering updates. This makes the bot send-only, which is
+            # safe when another instance owns the listener.
+            unschedule_bot_polling(bot.id)
+            await unregister_webhook(bot.token)
         bot.update_mode = body.update_mode
 
     session.add(bot)
@@ -406,7 +417,7 @@ def _bot_response(b: TelegramBot) -> dict:
         "bot_username": b.bot_username,
         "bot_id": b.bot_id,
         "webhook_path_id": b.webhook_path_id,
-        "update_mode": b.update_mode or "polling",
+        "update_mode": b.update_mode or "none",
         "token_preview": f"{b.token[:8]}...{b.token[-4:]}" if len(b.token) > 12 else "***",
         "created_at": b.created_at.isoformat(),
     }

packages/server/src/notify_bridge_server/database/migrations.py

@@ -144,7 +144,10 @@ async def migrate_schema(engine: AsyncEngine) -> None:
                 if bots:
                     logger.info("Backfilled webhook_path_id for %d existing bots", len(bots))
 
-            # Add update_mode to telegram_bot if missing
+            # Add update_mode to telegram_bot if missing.
+            # Existing bots pre-date this feature and were implicitly polling;
+            # preserve that behavior. New bots default to "none" via the
+            # SQLModel field default on fresh schemas.
             if not await _has_column(conn, "telegram_bot", "update_mode"):
                 await conn.execute(
                     text("ALTER TABLE telegram_bot ADD COLUMN update_mode TEXT DEFAULT 'polling'")

packages/server/src/notify_bridge_server/database/models.py

@@ -49,7 +49,7 @@ class TelegramBot(SQLModel, table=True):
     bot_username: str = Field(default="")
     bot_id: int = Field(default=0)
     webhook_path_id: str = Field(default_factory=lambda: uuid4().hex)
-    update_mode: str = Field(default="polling")  # "polling" or "webhook"
+    update_mode: str = Field(default="none")  # "none", "polling", or "webhook"
     # NOTE: commands_config column remains in the DB for backward compat,
     # but is no longer part of the SQLModel class. Data migrated to CommandConfig.
     created_at: datetime = Field(default_factory=_utcnow)

packages/server/src/notify_bridge_server/services/backup_schema.py

@@ -173,7 +173,7 @@ class TelegramBotData(BaseModel):
     token: str = ""
     icon: str = ""
     bot_username: str = ""
-    update_mode: str = "polling"
+    update_mode: str = "none"
 
 
 class MatrixBotData(BaseModel):