feat(provider) Add patched MiMo reasoning content support (#3298)

* Add patched MiMo reasoning content support

* Clarify MiMo patched model coverage

* Remove unused MiMo payload index

* Address MiMo review nits

backend/tests/test_model_factory.py

@@ -995,6 +995,41 @@ def test_openai_responses_api_settings_are_passed_to_chatopenai(monkeypatch):
     assert captured.get("output_version") == "responses/v1"
 
 
+# ---------------------------------------------------------------------------
+# Provider class path resolution
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.parametrize("model_id", ["mimo-v2.5-pro", "mimo-v2.5", "mimo-v2-flash"])
+def test_create_chat_model_resolves_patched_mimo_provider(model_id):
+    from deerflow.models.patched_mimo import PatchedChatMiMo
+
+    model = ModelConfig(
+        name=f"{model_id}-thinking",
+        display_name=f"{model_id} Thinking",
+        description=None,
+        use="deerflow.models.patched_mimo:PatchedChatMiMo",
+        model=model_id,
+        api_key="test-key",
+        base_url="https://api.xiaomimimo.com/v1",
+        supports_thinking=True,
+        when_thinking_enabled={"extra_body": {"thinking": {"type": "enabled"}}},
+        supports_vision=False,
+    )
+    cfg = _make_app_config([model])
+
+    chat_model = factory_module.create_chat_model(
+        name=f"{model_id}-thinking",
+        thinking_enabled=True,
+        app_config=cfg,
+        attach_tracing=False,
+    )
+
+    assert isinstance(chat_model, PatchedChatMiMo)
+    assert chat_model.model_name == model_id
+    assert chat_model.extra_body["thinking"]["type"] == "enabled"
+
+
 # ---------------------------------------------------------------------------
 # Duplicate keyword argument collision (issue #1977)
 # ---------------------------------------------------------------------------