fix(tg): reviewer fixes — error handling, timeouts, db index

- commands.py: try/except TelegramBadRequest around all Bot API calls (#2);
  /new handles "topics limit" with user-friendly message (#4)
- start.py: isolate _check_and_prune_stale_topics with try/except Exception (#3)
- message.py: asyncio.timeout(30) around stream_message; handle TimeoutError (#6)
- db.py: add idx_chats_user_id index in init_db() (#7)
- settings.py: remove dead active_chat_id variable (#8)
- tests: add test_message.py (stream error/success); add 2 tests in test_commands.py
  (topics limit, /archive in General topic)

adapter/telegram/handlers/settings.py

@@ -34,9 +34,6 @@ async def cb_settings_back(callback: CallbackQuery, state: FSMContext) -> None:
 
 @router.callback_query(F.data == "settings:skills")
 async def cb_skills(callback: CallbackQuery, state: FSMContext, dispatcher: EventDispatcher) -> None:
-    data = await state.get_data()
-    active_chat_id = data.get("active_chat_id", "")
-    # Get platform user id
     platform_user_id = str(callback.from_user.id)
 
     settings = await dispatcher._platform.get_settings(platform_user_id)