feat: emit template-style route stubs (async, body param, service hint)

Add generate_routes(template_style=...) and CLI --template-style. When on,
stubs use async def, a JSON body parameter named body (dict or Model), and
with --inject-request a service-lookup hint comment before NotImplementedError.
Default behaviour (def/payload) unchanged. +2 tests (32 passed), wiki + MCP
bundle regenerated.

tests/test_codegen_routes.py

@@ -197,3 +197,72 @@ def test_missing_operation_id_raises(tmp_path):
     )
     with pytest.raises(ValueError):
         generate_routes(spec, tmp_path / "routes")
+
+
+def test_template_style_async_body_model(tmp_path):
+    spec = _write_spec(
+        tmp_path,
+        _spec(
+            {
+                "/items": {
+                    "post": {
+                        "operationId": "create_item",
+                        "requestBody": {
+                            "required": True,
+                            "content": {
+                                "application/json": {
+                                    "schema": {"$ref": "#/components/schemas/ItemInput"}
+                                }
+                            },
+                        },
+                        "responses": {"201": {"description": "Created"}},
+                    }
+                }
+            },
+            {"ItemInput": {"type": "object", "properties": {"name": {"type": "string"}}}},
+        ),
+    )
+    files = generate_routes(
+        spec,
+        tmp_path / "routes",
+        use_models=True,
+        models_module="_gen.models",
+        inject_request=True,
+        template_style=True,
+    )
+    source = files[0].read_text(encoding="utf-8")
+    assert "async def create_item(request: Request, body: ItemInput, response: Response):" in source
+    assert "payload" not in source
+    assert "db_resources" in source
+    compile(source, str(files[0]), "exec")
+
+
+def test_template_style_dict_body_without_models(tmp_path):
+    spec = _write_spec(
+        tmp_path,
+        _spec(
+            {
+                "/items": {
+                    "post": {
+                        "operationId": "create_item",
+                        "requestBody": {
+                            "required": True,
+                            "content": {
+                                "application/json": {
+                                    "schema": {"$ref": "#/components/schemas/ItemInput"}
+                                }
+                            },
+                        },
+                        "responses": {"201": {"description": "Created"}},
+                    }
+                }
+            }
+        ),
+    )
+    files = generate_routes(
+        spec, tmp_path / "routes", inject_request=True, template_style=True
+    )
+    source = files[0].read_text(encoding="utf-8")
+    assert "async def create_item(request: Request, body: dict, response: Response):" in source
+    assert "payload" not in source
+    compile(source, str(files[0]), "exec")