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

tasks/c09/task.json

@@ -15,7 +15,7 @@
  ],
  "domain": "营销落地",
  "seed_meta": {
-  "ref_image_src": null
+  "ref_image_src": "prototypes/reference.jpg"
  },
  "title": "VIERI Fine Jewellery 落地页复刻与 GOLDVAULT 目录改造",
  "milestones": [