feat(接口4): 新增轮廓类型 contour_type + 提示词防漏键加固

- 豆包提示词追加「轮廓类型（轮廓偏曲/轮廓适中/轮廓偏直）」，_KEY_MAP 映射为 contour_type
- 提示词显式要求包含全部键：实测豆包随机漏键（面部年龄历史 ~26% 缺失），加固后 9/9 次全字段返回
- 同步接口文档/测试页至 7 字段；测试页顺带移除硬编码内部密码

static/test_interface4.html

@@ -112,10 +112,10 @@
 <script>
 const API_BASE = window.location.origin;
 
-const EN_KEYS = ['face_shape','eyebrow_shape','facial_age','dynamic_static_type','gender','gene_style'];
+const EN_KEYS = ['face_shape','eyebrow_shape','facial_age','dynamic_static_type','gender','gene_style','contour_type'];
 const EN_LABELS = {
   face_shape:'脸型', eyebrow_shape:'眉形', facial_age:'面部年龄',
-  dynamic_static_type:'动静类型', gender:'性别', gene_style:'基因风格'
+  dynamic_static_type:'动静类型', gender:'性别', gene_style:'基因风格', contour_type:'轮廓类型'
 };
 
 function $(id) { return document.getElementById(id); }
@@ -133,7 +133,7 @@ async function submitTest() {
   const fd = new FormData(); fd.append('image_file', f);
   const _reqStart = performance.now();
   try {
-    const r = await fetch(API_BASE + '/api/v1/face/features', { method:'POST', headers: { 'X-Internal-Token': 'dev-shared-secret-2026' }, body:fd });
+    const r = await fetch(API_BASE + '/api/v1/face/features', { method:'POST', body:fd });
     const json = await r.json();
     const _elapsed = ((performance.now() - _reqStart) / 1000).toFixed(2);
     $('jsonContent').textContent = JSON.stringify(json, null, 2);