feat(接口2): 新增生发后图片(ComfyUI/Flux inpaint)

在发际线预览基础上，每种发际线再出一张「植发3个月」生发图：

- hairline/mask.py: headmark 5步法遮罩(额头上部区域∩SegFormer头部=ROI，
  取发际线曲线以上闭合区域)；用 hairline_texture_black 渲染黑线替代手绘检测；
  compose_comfy_rgba 合成 RGBA(alpha=255-mask, 透明=重绘区, 对齐 ComfyUI mask=1-alpha)
- hairline/comfyui.py: ComfyUI 客户端(默认8182)，/upload/image+/prompt(改节点26+随机seed)
  +轮询/history+/view 取回生发图
- hairline/render.py: 抽出 build_overlay_layer 供遮罩取曲线像素
- hairline/service.py: extract_context 一次出 landmarks/parse_map/502点；
  generate_grow_results 每种=预览+生发图(同步串行N张，单张ComfyUI失败则grown置空不拖垮整请求)
- app.py: /hair/grow 返回 results[].grown_image_base64；重活放线程池避免卡事件循环
- add_hair.json 工作流 + hairline_texture_black/ 黑贴图入库
- 测试: test_mask.py(遮罩几何) + test_api mock ComfyUI 验 grown 字段，35 全绿

实测(5090): female 5张生发图同步约18s；预览/生发图人物五官服饰背景保持、黑线已清除。

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

hairline/comfyui.py

@@ -0,0 +1,110 @@
+"""ComfyUI 客户端：用 add_hair.json 工作流跑生发图（Flux-2 inpaint）。
+
+worker 不跑 Flux，只把「划线图 + 遮罩」的 RGBA 上传到本机 ComfyUI(默认 8182)，
+替换工作流节点 26 的输入图、随机 seed，提交 /prompt，轮询 /history，取回 /view 输出。
+"""
+from __future__ import annotations
+
+import copy
+import json
+import os
+import random
+import time
+import uuid
+
+import httpx
+
+COMFYUI_URL = os.getenv("COMFYUI_URL", "http://127.0.0.1:8182").rstrip("/")
+WORKFLOW_PATH = os.getenv(
+    "ADD_HAIR_WORKFLOW",
+    os.path.join(os.path.dirname(os.path.dirname(__file__)), "add_hair.json"),
+)
+COMFY_TIMEOUT = float(os.getenv("COMFYUI_TIMEOUT", "600"))   # 单张出图最长等待(秒)
+
+_INPUT_NODE = "26"     # LoadImage：外部输入图(含 alpha 遮罩)
+_SEED_NODE = "6"       # RandomNoise
+_OUTPUT_NODE = "17"    # SaveImage
+
+_workflow = None
+
+
+def _load_workflow() -> dict:
+    global _workflow
+    if _workflow is None:
+        with open(WORKFLOW_PATH, encoding="utf-8") as f:
+            _workflow = json.load(f)
+    return _workflow
+
+
+def run(rgba_png_bytes: bytes, timeout: float = COMFY_TIMEOUT) -> bytes:
+    """提交一次生发任务，返回输出 PNG 字节。失败抛异常。"""
+    client_id = uuid.uuid4().hex
+    with httpx.Client(base_url=COMFYUI_URL, timeout=30.0) as cli:
+        # 1. 上传输入图（含 alpha 遮罩）到 ComfyUI input 目录
+        fname = f"hair_{client_id}.png"
+        r = cli.post("/upload/image", files={"image": (fname, rgba_png_bytes, "image/png")},
+                     data={"overwrite": "true", "type": "input"})
+        r.raise_for_status()
+        up = r.json()
+        name = (up.get("subfolder") + "/" if up.get("subfolder") else "") + up["name"]
+
+        # 2. 改工作流：节点26 输入图 + 随机 seed
+        wf = copy.deepcopy(_load_workflow())
+        wf[_INPUT_NODE]["inputs"]["image"] = name
+        wf[_SEED_NODE]["inputs"]["noise_seed"] = random.randint(0, 2**63 - 1)
+
+        # 3. 提交
+        r = cli.post("/prompt", json={"prompt": wf, "client_id": client_id})
+        r.raise_for_status()
+        prompt_id = r.json()["prompt_id"]
+
+        # 4. 轮询 /history
+        deadline = time.time() + timeout
+        outputs = None
+        while time.time() < deadline:
+            hr = cli.get(f"/history/{prompt_id}")
+            hr.raise_for_status()
+            hist = hr.json()
+            if prompt_id in hist:
+                entry = hist[prompt_id]
+                status = entry.get("status", {})
+                if status.get("status_str") == "error":
+                    raise RuntimeError(f"ComfyUI 执行报错: {status}")
+                outputs = entry.get("outputs")
+                if outputs and _OUTPUT_NODE in outputs:
+                    break
+            time.sleep(1.0)
+        if not outputs or _OUTPUT_NODE not in outputs:
+            raise TimeoutError(f"ComfyUI 出图超时({timeout}s) prompt_id={prompt_id}")
+
+        # 5. 取回输出图
+        imgs = outputs[_OUTPUT_NODE].get("images") or []
+        if not imgs:
+            raise RuntimeError("ComfyUI 输出无图像")
+        info = imgs[0]
+        vr = cli.get("/view", params={"filename": info["filename"],
+                                      "subfolder": info.get("subfolder", ""),
+                                      "type": info.get("type", "output")})
+        vr.raise_for_status()
+        return vr.content
+
+
+def ping() -> bool:
+    """探测 ComfyUI 是否在线（/system_stats）。"""
+    try:
+        with httpx.Client(base_url=COMFYUI_URL, timeout=3.0) as cli:
+            return cli.get("/system_stats").status_code == 200
+    except Exception:  # noqa: BLE001
+        return False
+
+
+if __name__ == "__main__":
+    import sys
+    inp = sys.argv[1] if len(sys.argv) > 1 else "tests/output/comfy_input.png"
+    print("ComfyUI:", COMFYUI_URL, "online:", ping())
+    with open(inp, "rb") as f:
+        png = run(f.read())
+    out = "tests/output/grown.png"
+    with open(out, "wb") as f:
+        f.write(png)
+    print(f"生发图已存 {out}（{len(png)} bytes）")