Add reference design images, point task.json at relative paths

tasks/c38/task.json

@@ -14,7 +14,7 @@
  ],
  "domain": "预订服务",
  "seed_meta": {
-  "ref_image_src": null
+  "ref_image_src": "prototypes/reference.jpg"
  },
  "title": "Innovify 官网复刻 → 预约排期改造 → 品牌换肤",
  "milestones": [