fix: enable anthropic agent mode for tooling requests

Use agent ask_mode for Anthropic messages with tooling context so tool/write flows are executed, and add regression coverage plus docs/env updates for TOOL_FORWARD_ENABLED.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/test_tool_call_bridge.py

@@ -147,14 +147,18 @@ async def _collect_stream(response) -> str:
 class _SpyClient(_FakeClient):
     def __init__(self, *, stream_events: list[dict], complete_result: dict) -> None:
         super().__init__(stream_events=stream_events, complete_result=complete_result)
+        self.last_complete_args: tuple = ()
+        self.last_stream_args: tuple = ()
         self.last_complete_kwargs: dict = {}
         self.last_stream_kwargs: dict = {}
 
     async def chat_complete(self, *args, **kwargs) -> dict:
+        self.last_complete_args = tuple(args)
         self.last_complete_kwargs = dict(kwargs)
         return await super().chat_complete(*args, **kwargs)
 
     async def chat_stream(self, *args, **kwargs):
+        self.last_stream_args = tuple(args)
         self.last_stream_kwargs = dict(kwargs)
         async for event in super().chat_stream(*args, **kwargs):
             yield event
@@ -551,6 +555,40 @@ class ToolCallBridgeTests(unittest.IsolatedAsyncioTestCase):
         self.assertEqual(fake_cache.get_calls, [])
         self.assertEqual(fake_cache.put_calls, [])
 
+
+    async def test_anthropic_non_stream_with_tools_uses_agent_mode(self) -> None:
+        spy_client = _SpyClient(stream_events=[], complete_result={"text": "ok", "toolEvents": []})
+        req = AnthropicMessagesRequest(
+            model="claude-3-5-sonnet-20241022",
+            max_tokens=128,
+            messages=[{"role": "user", "content": "hi"}],
+            stream=False,
+            tools=[{"name": "write_file", "input_schema": {"type": "object", "properties": {}}}],
+            tool_choice={"type": "auto"},
+        )
+
+        with (
+            patch.object(main, "pool", _FakePool(_FakeInstance(spy_client))),
+            patch.object(main, "chat_guard", _FakeGuard()),
+            patch.object(main, "_ensure_instance_logged_in", AsyncMock(return_value={"id": "u"})),
+            patch.object(main.stats_collector, "record_chat", AsyncMock(return_value=None)),
+            patch.object(main.settings, "api_keys", ["test-key"]),
+            _SettingsPatch(tool_forward_enabled=True, default_ask_mode="chat"),
+        ):
+            await main.v1_messages(
+                req,
+                _make_request(
+                    "/v1/messages",
+                    headers={"x-api-key": "test-key", "anthropic-version": "2023-06-01"},
+                ),
+            )
+
+        self.assertIn("tool_config", spy_client.last_complete_kwargs)
+        cfg = spy_client.last_complete_kwargs["tool_config"]
+        self.assertEqual(cfg["provider"], "anthropic")
+        self.assertEqual(len(cfg["tools"]), 1)
+        self.assertEqual(spy_client.last_complete_args[2], "agent")
+
     async def test_anthropic_tooling_context_disables_session_reuse_cache(self) -> None:
         fake_cache = _FakeSessionCache()
         fake_client = _FakeClient(