fix(acp): defer attach notices until options are ready

Finish the awaited service-tier read before scheduling post-attach command
notices, so an editor has its session reply before the command menu. Read
the latest edit policy after that await for both reply representations.

The command-order regression fails on 42500a10d9. A second regression
catches mode changes during discovery. Both pass after the correction.

acp_adapter/gateway_server.py

@@ -300,22 +300,26 @@ class GatewayACPAgent(GatewayReplyMixin, acp.Agent):
         """Main's new/load/resume/fork reply fields (model picker, modes, provenance ``_meta``); the
         command list and context indicator follow once the reply is queued, as main scheduled them."""
         from acp_adapter.gateway_session_meta import model_state, provenance_meta, session_config_options, session_modes
-        from acp_adapter.modes import MODE_TO_EDIT_APPROVAL_POLICY
+        from acp_adapter.modes import EDIT_APPROVAL_POLICY_CONFIG_ID, MODE_TO_EDIT_APPROVAL_POLICY
         title = info.get("title")
         if isinstance(title, str) and title.strip():
             self._titles[session_id] = title
         models = await asyncio.to_thread(model_state, info)
         meta = await asyncio.to_thread(provenance_meta, self._home / "state.db", editor_id, session_id)
+        mode = self._modes.setdefault(session_id, session_modes(info).current_mode_id)
+        options = await session_config_options(self._gateway, session_id, models, info, mode)
+        # ``_adopt`` seeded the mode from the snapshot: a change the pump projected since is what the reply shows.
+        policy = MODE_TO_EDIT_APPROVAL_POLICY[self._modes[session_id]]
+        modes = session_modes({"edit_approval_policy": policy})
+        for option in options:
+            if option.id == EDIT_APPROVAL_POLICY_CONFIG_ID:
+                option.current_value = policy
         if self._conn:
             task = asyncio.get_running_loop().create_task(self._after_attach(session_id, editor_id))
             self._background.add(task)
             task.add_done_callback(self._background.discard)
-        # ``_adopt`` seeded the mode from the snapshot: a change the pump projected since is what the reply shows.
-        modes = session_modes({"edit_approval_policy": MODE_TO_EDIT_APPROVAL_POLICY[self._modes.setdefault(
-            session_id, session_modes(info).current_mode_id)]})
         return {"models": models, "modes": modes, "field_meta": meta,
-                "config_options": await session_config_options(
-                    self._gateway, session_id, models, info, modes.current_mode_id)}
+                "config_options": options}
 
     async def _after_attach(self, session_id, editor_id):
         from acp_adapter.gateway_session_meta import available_commands_update

tests/acp_adapter/test_gateway_attach_notice_order.py

@@ -0,0 +1,56 @@
+"""Attach command notices follow the reply even when speed discovery yields."""
+import asyncio
+from unittest.mock import AsyncMock
+
+import pytest
+
+from acp_adapter.gateway_server import GatewayACPAgent
+
+
+@pytest.mark.asyncio
+async def test_speed_discovery_does_not_publish_commands_before_the_attach_reply(monkeypatch):
+    monkeypatch.setattr('acp_adapter.gateway_session_meta.model_state', lambda info: None)
+    monkeypatch.setattr('acp_adapter.gateway_session_meta.provenance_meta', lambda *args: None)
+    agent = GatewayACPAgent()
+    reply_returned = False
+    command_order = []
+
+    async def session_update(*, session_id, update):
+        if update.session_update == 'available_commands_update':
+            command_order.append(reply_returned)
+
+    async def rpc(method, **params):
+        if method == 'config.get':
+            await asyncio.gather(*tuple(agent._background))
+            return {'value': 'normal', 'options': ['normal', 'fast']}
+        return {}
+
+    owner = AsyncMock()
+    owner.rpc.side_effect = rpc
+    agent._gateway = owner
+    monkeypatch.setattr(agent, '_client', AsyncMock(return_value=owner))
+    agent._conn = AsyncMock()
+    agent._conn.session_update.side_effect = session_update
+    fields = await agent._session_fields('session', {'model': 'gpt-6.1-sol'}, 'session')
+    reply_returned = True
+    await asyncio.gather(*tuple(agent._background))
+    assert any(option.id == 'service_tier' for option in fields['config_options'])
+    assert command_order == [True]
+
+
+@pytest.mark.asyncio
+async def test_mode_changed_during_speed_discovery_is_used_by_the_attach_reply(monkeypatch):
+    monkeypatch.setattr('acp_adapter.gateway_session_meta.model_state', lambda info: None)
+    monkeypatch.setattr('acp_adapter.gateway_session_meta.provenance_meta', lambda *args: None)
+    agent = GatewayACPAgent()
+
+    async def rpc(method, **params):
+        await agent._project_mode('session', 'session', {'edit_approval_policy': 'session'})
+        return {'value': 'normal', 'options': ['normal', 'fast']}
+
+    owner = AsyncMock()
+    owner.rpc.side_effect = rpc
+    agent._gateway = owner
+    fields = await agent._session_fields('session', {'model': 'gpt-6.1-sol'}, 'session')
+    assert fields['modes'].current_mode_id == 'dont_ask'
+    assert next(option for option in fields['config_options'] if option.category == 'mode').current_value == 'session'