feat(接口2/3): 加 use_mask 开关用于遮罩对比；网关回退纯透传

- 接口3 generate_grow_b 增加 use_mask（默认 true）：false 跳过检测、
  直接送划线图（空遮罩）
- 接口2 generate_grow_results 增加 use_mask：false 用干净原图+空遮罩，
  只跑一次 ComfyUI、N 项复用
- app.py 接口2/3 增加 use_mask form 参数并透传
- gateway/app.py 回退为纯透传（移除 OpenAPI schema 注入，请求体原样转发）
- docs 补 use_mask 说明

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

gateway/app.py

@@ -214,8 +214,7 @@ def _proxy(request: Request, path: str):
     return proxy_request(request, path)
 
 
-# 声明各接口的 form 参数 → 注入 OpenAPI schema（实际转发直接读 Request body，不在此解析）。
-# 每项字段：type(file/string/boolean)、description，可选 required(默认否)/default。
+# 声明各接口的 form 参数用于 OpenAPI schema（实际转发直接读 Request）
 _MEASURE_FORMS = {
     "image_file": {"type": "file", "description": "上传图片文件（JPG/PNG，≤ 1 MB）"},
     "image_url": {"type": "string", "description": "图片 URL"},
@@ -224,31 +223,13 @@ _MEASURE_FORMS = {
 
 _GROW_FORMS = {
     **_MEASURE_FORMS,
-    "gender": {"type": "string", "description": "性别 male/female（必填）", "required": True},
-    "beauty_enabled": {"type": "boolean", "description": "是否开启美颜（本期不生效）", "default": False},
+    "beauty_enabled": {"type": "boolean", "description": "是否开启美颜效果"},
 }
 
 _GROW_B_FORMS = {
-    "marked_image_file": {"type": "file", "description": "划线图片文件（JPG/PNG，≤ 1 MB）"},
+    "marked_image_file": {"type": "file", "description": "划线图片文件"},
     "marked_image_url": {"type": "string", "description": "划线图片 URL"},
     "marked_image_base64": {"type": "string", "description": "划线图片 base64"},
-    "use_mask": {"type": "boolean",
-                 "description": "是否启用自动检测遮罩，默认 true；false 跳过检测直接送图（空遮罩），测试对比用",
-                 "default": True},
-}
-
-_HAIRLINE_FORMS = {
-    **_MEASURE_FORMS,
-    "gender": {"type": "string", "description": "性别 male/female（必填）", "required": True},
-}
-
-# 路由(path, method) → form 参数表，供 custom_openapi 注入 requestBody。
-# 接口4(/api/v1/face/features) 在网关本地用 Form() 声明，FastAPI 自动生成 schema，不在此列。
-_ROUTE_FORMS = {
-    ("/api/v1/face/measure", "post"): _MEASURE_FORMS,
-    ("/api/v1/hair/grow", "post"): _GROW_FORMS,
-    ("/api/v1/hair/grow-b", "post"): _GROW_B_FORMS,
-    ("/api/v1/hairline/generate", "post"): _HAIRLINE_FORMS,
 }
 
 
@@ -339,49 +320,3 @@ async def face_features(
 async def hairline_generate(request: Request):
     """接口5：发际线PNG生成"""
     return await _proxy(request, "/api/v1/hairline/generate")
-
-
-# ---------------------------------------------------------------------------
-# 自定义 OpenAPI：代理路由用 Request 透传、不声明 Form，FastAPI 默认生成不出入参。
-# 这里把 _ROUTE_FORMS 注入各路由的 multipart/form-data requestBody，使 /docs 入参完整。
-# ---------------------------------------------------------------------------
-
-
-def _form_schema(forms: dict) -> dict:
-    """form 参数表 → multipart/form-data 的 JSON Schema。"""
-    props, required = {}, []
-    for name, spec in forms.items():
-        prop = ({"type": "string", "format": "binary"} if spec["type"] == "file"
-                else {"type": spec["type"]})
-        if spec.get("description"):
-            prop["description"] = spec["description"]
-        if "default" in spec:
-            prop["default"] = spec["default"]
-        props[name] = prop
-        if spec.get("required"):
-            required.append(name)
-    schema = {"type": "object", "properties": props}
-    if required:
-        schema["required"] = required
-    return schema
-
-
-def custom_openapi():
-    if app.openapi_schema:
-        return app.openapi_schema
-    from fastapi.openapi.utils import get_openapi
-
-    schema = get_openapi(title=app.title, version=app.version,
-                         description=app.description, routes=app.routes)
-    for (path, method), forms in _ROUTE_FORMS.items():
-        op = schema.get("paths", {}).get(path, {}).get(method)
-        if op is not None:
-            op["requestBody"] = {
-                "required": True,
-                "content": {"multipart/form-data": {"schema": _form_schema(forms)}},
-            }
-    app.openapi_schema = schema
-    return schema
-
-
-app.openapi = custom_openapi