feat: 接口1/6 发际线贴近头顶时改为修正而非弃用置null

顶庭(头顶→发际线)<0.7cm 时不再返回 null：
- 上庭 = 0.95×中庭 反推发际线；若越过头顶则顶庭固定 0.7cm（发际线钉在头顶下方）
- hairline_source 新增 "corrected"；to_response 始终输出完整四庭
- 标注图始终正常画发际线横线与庭段
- 接口6 三庭逻辑同步，去 discarded 分支

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

face_analysis/annotation.py

@@ -212,11 +212,9 @@ def create_annotated_image(image_bgr, measure_result, ear_mask=None, hair_mask=N
 
     buf = np.zeros((h, w, 4), dtype=np.uint8)
 
-    # 发际线弃用（hairline_discarded）：保留头顶横线，去掉发际线横线，
-    # 也不标顶/上庭（缺发际线作边界，算不出）。横线 = 头顶/眉心/鼻翼下缘/下巴尖。
-    if getattr(measure_result, "hairline_discarded", False):
-        order = ["hair_top", "brow_center", "nose_bottom", "chin_tip"]
-    elif variant == "v6":
+    # 横线：v1 = 头顶/发际线/眉心/鼻翼下缘/下巴尖；v6 = 发际线/眉心/鼻翼下缘/下巴尖。
+    # （发际线贴近头顶时已在 MeasureResult 修正 vertical，此处始终正常画发际线。）
+    if variant == "v6":
         order = ["hairline", "brow_center", "nose_bottom", "chin_tip"]
     else:
         order = ["hair_top", "hairline", "brow_center", "nose_bottom", "chin_tip"]
@@ -243,7 +241,7 @@ def create_annotated_image(image_bgr, measure_result, ear_mask=None, hair_mask=N
     face_cx = (fx0 + fx1) / 2
     over = max(6, round(s * 0.030))           # 线超出包围盒的长度（参考图风格）
     face_half = (fx1 - fx0) / 2 + over        # 横线超出最外侧竖线一点
-    # 竖线纵向范围：v6 = 发际线→下巴尖（不超出）；v1（含发际线弃用）= 头顶→下巴尖并两端超出一点
+    # 竖线纵向范围：v6 = 发际线→下巴尖（不超出）；v1 = 头顶→下巴尖并两端超出一点
     v_top = fy0 if variant == "v6" else fy0 - over
     v_bot = fy1 if variant == "v6" else fy1 + over
 
@@ -281,14 +279,8 @@ def create_annotated_image(image_bgr, measure_result, ear_mask=None, hair_mask=N
         draw.text((x, ys[i]), text, fill=LINE_COLOR, font=font, anchor="lm")
 
     # --- 3b. 左侧四庭：名 + 数值两行（无 cm）+ 竖向虚线双箭头 ---
-    # court_start：庭段在 order 里的起始索引。发际线弃用时 order 首位是头顶（无下界发际线，
-    # 顶/上庭不标），中庭从眉心开始 → 跳过 order[0]。
-    if getattr(measure_result, "hairline_discarded", False):
-        court_cm = [measure_result.middle_cm, measure_result.lower_cm]
-        court_name = ["中庭", "下庭"]
-        n_court = 2
-        court_start = 1
-    elif variant == "v6":
+    # court_start：庭段在 order 里的起始索引。v6 为三庭（无顶庭），其余四庭。
+    if variant == "v6":
         court_cm = [measure_result.upper_cm, measure_result.middle_cm, measure_result.lower_cm]
         court_name = ["上庭", "中庭", "下庭"]
         n_court = 3

face_analysis/measure.py

@@ -153,10 +153,12 @@ def pt_or_none(vertical, name):
 class MeasureResult:
     """测量结果，提供 to_response() 输出与接口文档同构的 data 字段。"""
 
-    # 发际线弃用阈值：发际线离头顶（顶庭）< 此值时判定分割不可靠，弃用发际线。
-    # hairline 与 hair_top 几乎重合（如稀疏头发中轴漏检只剩一小撮），说明发际线
-    # 定位无意义 → 顶/上庭置 null、标注图不画头顶/发际线。
-    HAIRLINE_DISCARD_TOP_CM = 0.7
+    # 发际线修正阈值/固定值：发际线离头顶（顶庭）< 此值时判定分割不可靠，需修正发际线。
+    # hairline 与 hair_top 几乎重合（如稀疏头发中轴漏检只剩一小撮）→ 上庭改取
+    # 0.95×中庭反推发际线；若反推后越过头顶，则顶庭固定为 0.7cm（发际线钉在头顶下方
+    # 0.7cm），上庭取眉心→发际线剩余距离。修正后始终返回完整四庭，不再置 null。
+    HAIRLINE_CORRECT_TOP_CM = 0.7
+    UPPER_TO_MIDDLE_RATIO = 0.95   # 贴近头顶时，上庭 = 中庭 × 此比例
 
     def __init__(self, vertical, eyes, px_per_cm, hairline_source, head_pose,
                  landmarks=None, image_width=None, image_height=None):
@@ -170,19 +172,32 @@ class MeasureResult:
         self.w = image_width
         self.h = image_height
 
-        # 各庭厘米
+        # 发际线修正：顶庭（头顶→发际线）< 阈值视为发际线贴近头顶、不可靠。
+        # 改写：上庭 = 0.95×中庭 → 由眉心反推发际线 y；若发际线越过头顶
+        # （hairline_y < hair_top_y），顶庭固定为 0.7cm（发际线钉在头顶下方 0.7cm）。
+        # 回写 vertical，使 to_response/标注图/v6 复用全部拿到修正后的发际线。
+        self.detected_top_cm = vertical["top_court_px"] / px_per_cm
+        self.hairline_corrected = self.detected_top_cm < self.HAIRLINE_CORRECT_TOP_CM
+        if self.hairline_corrected:
+            brow_x, brow_y = vertical["brow_center"]
+            hair_top_y = vertical["hair_top"][1]
+            new_upper_px = vertical["middle_court_px"] * self.UPPER_TO_MIDDLE_RATIO
+            hairline_y = brow_y - new_upper_px
+            if hairline_y < hair_top_y:   # 反推发际线越过头顶 → 顶庭固定 0.7cm
+                hairline_y = hair_top_y + self.HAIRLINE_CORRECT_TOP_CM * px_per_cm
+                new_upper_px = brow_y - hairline_y
+            vertical["hairline"] = (brow_x, float(hairline_y))
+            vertical["upper_court_px"] = new_upper_px
+            vertical["top_court_px"] = hairline_y - hair_top_y
+            self.hairline_source = "corrected"
+
+        # 各庭厘米（修正后）
         self.top_cm = vertical["top_court_px"] / px_per_cm
         self.upper_cm = vertical["upper_court_px"] / px_per_cm
         self.middle_cm = vertical["middle_court_px"] / px_per_cm
         self.lower_cm = vertical["lower_court_px"] / px_per_cm
-        # 发际线弃用判定：顶庭（头顶→发际线）过小视为发际线贴近头顶、不可靠。
-        # 弃用时 hairline_source 改为 "discarded"，face_total 只算中庭+下庭。
-        self.hairline_discarded = self.top_cm < self.HAIRLINE_DISCARD_TOP_CM
-        if self.hairline_discarded:
-            self.hairline_source = "discarded"
-            self.face_total_cm = self.middle_cm + self.lower_cm
-        else:
-            self.face_total_cm = self.top_cm + self.upper_cm + self.middle_cm + self.lower_cm
+        self.face_total_cm = (self.top_cm + self.upper_cm
+                              + self.middle_cm + self.lower_cm)
 
         # 七眼厘米
         self.eye_width_cm = eyes["eye_width_px"] / px_per_cm
@@ -190,77 +205,41 @@ class MeasureResult:
         self.inter_eye_cm = eyes["inter_eye_distance_px"] / px_per_cm
 
     def to_response(self):
-        # 发际线弃用：顶/上庭相关字段置 null（保留键），ratio 分母只算中下庭；
-        # landmarks.hair_top/hairline 置 null。否则按四庭正常输出。
-        if self.hairline_discarded:
-            base_px = (self.vertical["middle_court_px"] + self.vertical["lower_court_px"])
-            data = {
-                "face_total_height_cm": round(self.face_total_cm, 2),
-                "four_courts": {
-                    "top_court_cm": None,
-                    "upper_court_cm": None,
-                    "middle_court_cm": round(self.middle_cm, 2),
-                    "lower_court_cm": round(self.lower_cm, 2),
-                    "ratios": {
-                        "top_court": None,
-                        "upper_court": None,
-                        "middle_court": round(self.vertical["middle_court_px"] / base_px, 3),
-                        "lower_court": round(self.vertical["lower_court_px"] / base_px, 3),
-                    },
+        # 四庭完整输出（发际线贴近头顶时已在 __init__ 修正 vertical，无 null 分支）。
+        total_px = (self.vertical["top_court_px"] + self.vertical["upper_court_px"]
+                    + self.vertical["middle_court_px"] + self.vertical["lower_court_px"])
+        data = {
+            "face_total_height_cm": round(self.face_total_cm, 2),
+            "four_courts": {
+                "top_court_cm": round(self.top_cm, 2),
+                "upper_court_cm": round(self.upper_cm, 2),
+                "middle_court_cm": round(self.middle_cm, 2),
+                "lower_court_cm": round(self.lower_cm, 2),
+                "ratios": {
+                    "top_court": round(self.vertical["top_court_px"] / total_px, 3),
+                    "upper_court": round(self.vertical["upper_court_px"] / total_px, 3),
+                    "middle_court": round(self.vertical["middle_court_px"] / total_px, 3),
+                    "lower_court": round(self.vertical["lower_court_px"] / total_px, 3),
                 },
-                "seven_eyes": {
-                    "eye_width_cm": round(self.eye_width_cm, 2),
-                    "face_width_cm": round(self.face_width_cm, 2),
-                    "inter_eye_distance_cm": round(self.inter_eye_cm, 2),
-                    "ratios": {
-                        "eye_width": round(self.eyes["eye_width_px"] / self.eyes["face_width_px"], 3),
-                        "inter_eye_distance": round(self.eyes["inter_eye_distance_px"] / self.eyes["face_width_px"], 3),
-                    },
+            },
+            "seven_eyes": {
+                "eye_width_cm": round(self.eye_width_cm, 2),
+                "face_width_cm": round(self.face_width_cm, 2),
+                "inter_eye_distance_cm": round(self.inter_eye_cm, 2),
+                "ratios": {
+                    "eye_width": round(self.eyes["eye_width_px"] / self.eyes["face_width_px"], 3),
+                    "inter_eye_distance": round(self.eyes["inter_eye_distance_px"] / self.eyes["face_width_px"], 3),
                 },
-                "landmarks": {
-                    "hair_top": None,
-                    "hairline": None,
-                    "brow_center": pt_or_none(self.vertical, "brow_center"),
-                    "nose_bottom": pt_or_none(self.vertical, "nose_bottom"),
-                    "chin_tip": pt_or_none(self.vertical, "chin_tip"),
-                },
-                "hairline_source": self.hairline_source,
-            }
-        else:
-            total_px = (self.vertical["top_court_px"] + self.vertical["upper_court_px"]
-                        + self.vertical["middle_court_px"] + self.vertical["lower_court_px"])
-            data = {
-                "face_total_height_cm": round(self.face_total_cm, 2),
-                "four_courts": {
-                    "top_court_cm": round(self.top_cm, 2),
-                    "upper_court_cm": round(self.upper_cm, 2),
-                    "middle_court_cm": round(self.middle_cm, 2),
-                    "lower_court_cm": round(self.lower_cm, 2),
-                    "ratios": {
-                        "top_court": round(self.vertical["top_court_px"] / total_px, 3),
-                        "upper_court": round(self.vertical["upper_court_px"] / total_px, 3),
-                        "middle_court": round(self.vertical["middle_court_px"] / total_px, 3),
-                        "lower_court": round(self.vertical["lower_court_px"] / total_px, 3),
-                    },
-                },
-                "seven_eyes": {
-                    "eye_width_cm": round(self.eye_width_cm, 2),
-                    "face_width_cm": round(self.face_width_cm, 2),
-                    "inter_eye_distance_cm": round(self.inter_eye_cm, 2),
-                    "ratios": {
-                        "eye_width": round(self.eyes["eye_width_px"] / self.eyes["face_width_px"], 3),
-                        "inter_eye_distance": round(self.eyes["inter_eye_distance_px"] / self.eyes["face_width_px"], 3),
-                    },
-                },
-                "landmarks": {
-                    "hair_top": pt_or_none(self.vertical, "hair_top"),
-                    "hairline": pt_or_none(self.vertical, "hairline"),
-                    "brow_center": pt_or_none(self.vertical, "brow_center"),
-                    "nose_bottom": pt_or_none(self.vertical, "nose_bottom"),
-                    "chin_tip": pt_or_none(self.vertical, "chin_tip"),
-                },
-                "hairline_source": self.hairline_source,
-            }
+            },
+            "landmarks": {
+                "hair_top": pt_or_none(self.vertical, "hair_top"),
+                "hairline": pt_or_none(self.vertical, "hairline"),
+                "brow_center": pt_or_none(self.vertical, "brow_center"),
+                "nose_bottom": pt_or_none(self.vertical, "nose_bottom"),
+                "chin_tip": pt_or_none(self.vertical, "chin_tip"),
+            },
+            "hairline_source": self.hairline_source,
+        }
         # left/right_position：mediapipe 21/251 号定位点（原图像素，与 landmarks 同坐标系）。
         # landmarks 缺省（如测试直构 MeasureResult）时不输出，保持向后兼容。
         if self.landmarks is not None and self.w and self.h: