fix(pairing): persist shortcut commands and avoid Feishu side effects

- AgentLoop._state_command now persists user message and assistant
  response for shortcut commands (e.g. /pairing) so WebUI history
  hydration after _turn_end no longer shows an empty chat.  /new is
  excluded because it intentionally clears the session.

- Feishu _on_message sends pairing codes for unauthorized DMs before
  any media side effects (reactions, downloads, transcription).
  Group chat unauthorized senders are still silently ignored early.

- Update test_feishu_reply to assert the new DM pairing behavior.

nanobot/channels/feishu.py

@@ -1712,6 +1712,18 @@ class FeishuChannel(BaseChannel):
             while len(self._processed_message_ids) > 1000:
                 self._processed_message_ids.popitem(last=False)
 
+            # Early permission check — avoid side effects for unauthorized users.
+            # Group chats are silently ignored; DMs get a pairing code.
+            if not self.is_allowed(sender_id):
+                if chat_type == "p2p":
+                    await self._handle_message(
+                        sender_id=sender_id,
+                        chat_id=sender_id,
+                        content="",
+                        is_dm=True,
+                    )
+                return
+
             # Add reaction (non-blocking — tracked background task)
             task = asyncio.create_task(
                 self._add_reaction(message_id, self.config.react_emoji)

tests/channels/test_feishu_reply.py

@@ -911,7 +911,8 @@ def test_on_background_task_done_removes_from_set() -> None:
 
 
 @pytest.mark.asyncio
-async def test_on_message_ignores_unauthorized_sender_before_side_effects() -> None:
+async def test_on_message_unauthorized_dm_sends_pairing_code_without_side_effects() -> None:
+    """Unauthorized DM sender gets a pairing code but no media side effects."""
     channel = _make_feishu_channel(group_policy="open")
     channel.config.allow_from = ["ou_allowed"]
     channel._add_reaction = AsyncMock()
@@ -927,6 +928,32 @@ async def test_on_message_ignores_unauthorized_sender_before_side_effects() -> N
 
     await channel._on_message(event)
 
+    channel._add_reaction.assert_not_awaited()
+    channel._download_and_save_media.assert_not_awaited()
+    channel.transcribe_audio.assert_not_awaited()
+    # _handle_message is called to issue the pairing code in DMs
+    channel._handle_message.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_on_message_unauthorized_group_ignored_before_side_effects() -> None:
+    """Unauthorized group chat sender is silently ignored before any side effects."""
+    channel = _make_feishu_channel(group_policy="open")
+    channel.config.allow_from = ["ou_allowed"]
+    channel._add_reaction = AsyncMock()
+    channel._download_and_save_media = AsyncMock(return_value=("/tmp/audio.ogg", "[audio]"))
+    channel.transcribe_audio = AsyncMock(return_value="transcript")
+    channel._handle_message = AsyncMock()
+
+    event = _make_feishu_event(
+        chat_type="group",
+        msg_type="audio",
+        content='{"file_key": "file_1"}',
+        sender_open_id="ou_blocked",
+    )
+
+    await channel._on_message(event)
+
     channel._add_reaction.assert_not_awaited()
     channel._download_and_save_media.assert_not_awaited()
     channel.transcribe_audio.assert_not_awaited()