feat(tg): forum-first adapter complete — handlers, bot.py, 46 tests pass

adapter/telegram/handlers/start.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+import structlog
+from aiogram import Router
+from aiogram.exceptions import TelegramBadRequest
+from aiogram.filters import CommandStart
+from aiogram.types import Message
+
+from adapter.telegram import db
+
+logger = structlog.get_logger(__name__)
+
+router = Router(name="start")
+
+
+@router.message(CommandStart())
+async def cmd_start(message: Message) -> None:
+    """
+    Bootstrap the user's forum.
+
+    First visit: create Чат #1, hide General topic.
+    Returning visit: health-check all active topics, archive stale ones.
+    """
+    user_id = message.from_user.id
+    chat_id = message.chat.id
+
+    await _check_and_prune_stale_topics(message, user_id, chat_id)
+
+    active = db.get_active_chats(user_id)
+
+    if not active:
+        try:
+            topic = await message.bot.create_forum_topic(chat_id=chat_id, name="Чат #1")
+            thread_id = topic.message_thread_id
+            db.create_chat(user_id=user_id, thread_id=thread_id, chat_name="Чат #1")
+            logger.info("start_created_first_topic", user_id=user_id, thread_id=thread_id)
+        except TelegramBadRequest as e:
+            logger.warning("start_create_topic_failed", error=str(e))
+            await message.answer(
+                "Не удалось создать топик. Убедись, что в @BotFather включён "
+                "Threaded Mode для этого бота."
+            )
+            return
+
+        try:
+            await message.bot.hide_general_forum_topic(chat_id=chat_id)
+        except TelegramBadRequest:
+            pass  # Not critical
+
+        await message.answer(
+            "Привет! Это твоё личное пространство с AI-агентом Lambda. "
+            "Каждый топик — отдельный контекст. Напиши что-нибудь."
+        )
+    else:
+        await message.answer(
+            f"Снова привет! У тебя {len(active)} активных чатов. "
+            "Напиши /new чтобы создать новый."
+        )
+
+
+async def _check_and_prune_stale_topics(
+    message: Message, user_id: int, chat_id: int
+) -> None:
+    """Send typing action to each active topic; archive any that no longer exist."""
+    for chat in db.get_active_chats(user_id):
+        thread_id = chat["thread_id"]
+        try:
+            await message.bot.send_chat_action(
+                chat_id=chat_id,
+                action="typing",
+                message_thread_id=thread_id,
+            )
+        except TelegramBadRequest:
+            db.archive_chat(user_id=user_id, thread_id=thread_id)
+            logger.info("pruned_stale_topic", user_id=user_id, thread_id=thread_id)