refactor: split TG worker into poller (callbacks) and sender (email summaries) threads

src/tg_bot.py

@@ -86,8 +86,8 @@ def poll_telegram(tg_cfg: TelegramConfig, cfg: Config, last_update_id: int) -> i
     try:
         resp = requests.get(
             f"https://api.telegram.org/bot{tg_cfg.bot_token}/getUpdates",
-            params={"offset": last_update_id, "timeout": 10},
-            timeout=15,
+            params={"offset": last_update_id, "timeout": 2, "allowed_updates": ["callback_query", "message"]},
+            timeout=5,
         )
         resp.raise_for_status()
         data = resp.json()