Contributor credits, SVG prefetch, integrate Xiaomi MiMo from PR #4

- Runs gain a contributor field (GitHub username); the site renders an
  avatar chip linked to their profile next to each run's notes, and CI
  validates the field. All existing runs are attributed.
- SVG variants of a case are prefetched during idle time, so switching
  model tabs swaps images without a network hiccup.
- Xiaomi MiMo v2.5 Pro (Claude Code, max effort) integrated from PR #4
  with both case runs and provenance notes; README registry tables
  updated.

Co-authored-by: DuJiabao <Jiabao.du@Yunzhisun.com>

models/doubao-seed-2-0-mini.json

@@ -9,7 +9,8 @@
       "note": {
         "zh": "在豆包网页版以快速模式一次生成。\n\n「要不要我再给你做一个带简单动画（翅膀扇动、车轮转动）的增强版 SVG 代码？」",
         "en": "Generated in one shot on Doubao web app in Lite mode.\n\n\"Should I make you an enhanced version of the SVG code with simple animations (flapping wings, rotating wheels)?\""
-      }
+      },
+      "contributor": "LpIuma"
     }
   }
 }