Please address the comments from this code review:

## Overall Comments
- The reconnect logic in `run()` currently sleeps for a fixed 2 seconds after any `aiohttp.ClientConnectionError`; consider using a simple backoff strategy (or making the delay configurable) so that repeated failures don't result in a tight reconnect loop or unnecessarily long pauses.
- Typing session state in `_typing_states` is never pruned for users that no longer have owners/tasks; you may want to drop empty `TypingSessionState` entries once both `owners` and associated tasks are cleared to avoid unbounded growth over long-running processes.

## Individual Comments

### Comment 1
<location path="astrbot/core/platform/sources/weixin_oc/weixin_oc_adapter.py" line_range="53" />
<code_context>
     error: str | None = None


+@dataclass
+class TypingSessionState:
+    ticket: str | None = None
</code_context>
<issue_to_address>
**issue (complexity):** Consider extracting the new typing-related logic into a dedicated manager and clarifying TypingSessionState transitions to keep the adapter simpler and the state machine easier to follow.

You can reduce the new complexity substantially by explicitly encapsulating the typing orchestration, while keeping behavior identical.

### 1. Extract a dedicated typing manager

Right now `WeixinOCAdapter` owns:

- `_typing_states`
- `TypingSessionState`
- all the orchestration methods (`_get_typing_state`, `_ensure_typing_ticket`, `_run_typing_keepalive`, `start_typing`, `stop_typing`, `_cleanup_typing_tasks`, …)

You can move these into a small helper class that the adapter delegates to. This keeps the adapter focused on login/polling/message handling and isolates the state machine.

Example sketch:

```python
@dataclass
class TypingSessionState:
    ticket: str | None = None
    ticket_context_token: str | None = None
    refresh_after: float = 0.0
    keepalive_task: asyncio.Task | None = None
    cancel_task: asyncio.Task | None = None
    owners: set[str] = field(default_factory=set)
    lock: asyncio.Lock = field(default_factory=asyncio.Lock)


class WeixinTypingManager:
    def __init__(
        self,
        client: WeixinOCClient,
        *,
        adapter_id: str,
        shutdown_event: asyncio.Event,
        keepalive_interval_s: int,
        ticket_ttl_s: int,
        context_tokens: dict[str, str],
    ) -> None:
        self._client = client
        self._adapter_id = adapter_id
        self._shutdown_event = shutdown_event
        self._keepalive_interval_s = keepalive_interval_s
        self._ticket_ttl_s = ticket_ttl_s
        self._context_tokens = context_tokens
        self._states: dict[str, TypingSessionState] = {}

    # move _get_typing_state, _typing_supported_for, _ensure_typing_ticket,
    # _send_typing_state, _run_typing_keepalive, _typing_keepalive_loop,
    # _delayed_cancel_typing, start_typing, stop_typing, _cleanup_typing_tasks
    # into methods here, switching self.client → self._client,
    # self.meta().id → self._adapter_id, self._typing_states → self._states, etc.
```

Adapter usage then becomes a small surface:

```python
class WeixinOCAdapter(Platform):
    def __init__(...):
        ...
        self._typing_manager = WeixinTypingManager(
            client=self.client,
            adapter_id=self.meta().id,
            shutdown_event=self._shutdown_event,
            keepalive_interval_s=self._typing_keepalive_interval_s,
            ticket_ttl_s=self._typing_ticket_ttl_s,
            context_tokens=self._context_tokens,
        )

    async def start_typing(self, user_id: str, owner_id: str) -> None:
        await self._typing_manager.start_typing(user_id, owner_id)

    async def stop_typing(self, user_id: str, owner_id: str) -> None:
        await self._typing_manager.stop_typing(user_id, owner_id)

    async def run(self) -> None:
        ...
        finally:
            await self._typing_manager.cleanup()
            await self.client.close()

    async def terminate(self) -> None:
        self._shutdown_event.set()
        await self._typing_manager.cleanup()
```

This is mostly mechanical (rename `self` references, pass dependencies via `__init__`) and does not change behavior, but it cuts the adapter’s responsibility surface significantly.

### 2. Localize state transitions on `TypingSessionState`

A lot of complexity comes from repeated patterns manipulating `owners`, `keepalive_task`, and `cancel_task` under locks. You can move these into small methods on `TypingSessionState` (or on the manager operating on a single state) to make the state machine more explicit and reduce repeated branching.

For example:

```python
@dataclass
class TypingSessionState:
    ...
    # Invariants:
    # - if owners is empty, keepalive_task is None
    # - cancel_task is only non-None while a cancel is scheduled but not sent/completed

    def has_active_owners(self) -> bool:
        return bool(self.owners)

    def add_owner(self, owner_id: str) -> bool:
        """Returns True if this transitioned from 0 → 1 owners."""
        before = len(self.owners)
        self.owners.add(owner_id)
        return before == 0 and len(self.owners) == 1

    def remove_owner(self, owner_id: str) -> bool:
        """Returns True if this transitioned from 1 → 0 owners."""
        if owner_id not in self.owners:
            return False
        self.owners.remove(owner_id)
        return not self.owners
```

Then `start_typing` / `stop_typing` logic becomes easier to follow:

```python
async def start_typing(self, user_id: str, owner_id: str) -> None:
    state = self._get_typing_state(user_id)
    cancel_task: asyncio.Task | None = None

    async with state.lock:
        if not self._typing_supported_for(user_id):
            return
        first_owner = state.add_owner(owner_id)
        if not first_owner:
            # already active; nothing else to do
            return
        # remaining logic unchanged, but now you know this is the 0→1 transition
```

```python
async def stop_typing(self, user_id: str, owner_id: str) -> None:
    state = self._states.get(user_id)
    if state is None:
        return

    task: asyncio.Task | None = None
    async with state.lock:
        last_owner = state.remove_owner(owner_id)
        if not last_owner:
            return
        task = state.keepalive_task
        state.keepalive_task = None
    ...
```

This doesn’t change semantics but encodes the important transitions (`0→1`, `1→0`) explicitly, so you don’t need to mentally reconstruct them from raw set length checks in multiple places.

### 3. Use `_cancel_task_safely` consistently

You already created `_cancel_task_safely`, but some places still cancel tasks directly and await later. Centralizing the pattern makes the async lifecycle easier to reason about and eliminates subtle differences.

Example in `_cleanup_typing_tasks`:

```python
async def _cleanup_typing_tasks(self) -> None:
    tasks: list[asyncio.Task] = []
    cancels: list[tuple[str, str]] = []

    for user_id, state in list(self._states.items()):
        ...
        if state.keepalive_task is not None:
            tasks.append(state.keepalive_task)
            state.keepalive_task = None
        if state.cancel_task is not None:
            tasks.append(state.cancel_task)
            state.cancel_task = None

    for task in tasks:
        await self._cancel_task_safely(
            task,
            log_message="weixin_oc(%s): typing cleanup failed",
            log_args=(self._adapter_id,),
        )
```

If you move the logic into the manager, it’s easy to ensure that any place that cancels tasks uses this helper, instead of mixing direct `task.cancel()` calls with separate awaiting logic.

---

These steps keep all current behavior (including error handling and retry semantics) but:

- decouple typing from the adapter,
- make the per-user state machine explicit,
- and concentrate task/lock orchestration in a single, smaller component.
</issue_to_address>