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/message.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import asyncio
 import time
 
 import structlog
@@ -46,22 +47,26 @@ async def handle_topic_message(message: Message, dispatcher: EventDispatcher) ->
     last_edit_len = 0
 
     try:
-        async for chunk in dispatcher._platform.stream_message(
-            user_id=platform_user.user_id,
-            chat_id=str(thread_id),
-            text=incoming.text,
-            attachments=None,
-        ):
-            accumulated += chunk.delta
-            now = time.monotonic()
-            delta = len(accumulated) - last_edit_len
-            if delta >= STREAM_MIN_DELTA and (now - last_edit_time) >= STREAM_EDIT_INTERVAL:
-                await _safe_edit(placeholder, accumulated)
-                last_edit_time = now
-                last_edit_len = len(accumulated)
+        async with asyncio.timeout(30):
+            async for chunk in dispatcher._platform.stream_message(
+                user_id=platform_user.user_id,
+                chat_id=str(thread_id),
+                text=incoming.text,
+                attachments=None,
+            ):
+                accumulated += chunk.delta
+                now = time.monotonic()
+                delta = len(accumulated) - last_edit_len
+                if delta >= STREAM_MIN_DELTA and (now - last_edit_time) >= STREAM_EDIT_INTERVAL:
+                    await _safe_edit(placeholder, accumulated)
+                    last_edit_time = now
+                    last_edit_len = len(accumulated)
 
-        await _safe_edit(placeholder, accumulated or "...")
+            await _safe_edit(placeholder, accumulated or "...")
 
+    except TimeoutError:
+        logger.warning("platform_timeout", user_id=user_id, thread_id=thread_id)
+        await _safe_edit(placeholder, "Сервис не отвечает, попробуй позже")
     except TelegramBadRequest as e:
         if "thread not found" in str(e).lower():
             db.archive_chat(user_id=user_id, thread_id=thread_id)