Data-only contributions: per-model JSON registry, validation, PR CI

Contributors no longer touch site code. Model registration moves from
cases.ts literals to repo-root models/<model-id>.json files (filename =
model id = outputs/ folder); cases move to cases.json; cases.ts now just
derives MODELS/RUNS via import.meta.glob. Parallel PRs stop conflicting
because each model owns its own file.

scripts/validate-data.ts runs inside `bun run build` and a new PR CI
workflow: dash-only ids, required bilingual provenance note per run,
declared artifacts must exist, no orphan outputs/ dirs.

Also: run notes render whitespace-pre-wrap (multi-line notes, idea from
PR #2), README contribution guide rewritten around the JSON template,
CLAUDE.md updated, OG card refreshed for the DeepSeek merge.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

models/grok-build.json

@@ -0,0 +1,13 @@
+{
+  "label": "Grok Build",
+  "vendor": "xAI",
+  "order": 60,
+  "runs": {
+    "mythos-craft": {
+      "note": {
+        "zh": "在本地通过 Grok Build（TUI）开发实现；本页为修复版（共改 3 行）。问题一：第 82 行 const WORLD_SEED = 0xAETHER，T/H/R 不是十六进制字符，整段脚本解析即抛 SyntaxError——修复前画面纯黑，只剩 HTML 文字。问题二：贴图集画在 canvas 顶部两行、UV 按左上原点计算，却未设 flipY=false，所有面采样到未绘制的黑色区域——修复前进入世界后近处地形全黑。问题三：forward 向量已指向相机朝向，按键却写成 W 减、S 加——修复前按 W 后退、按 S 前进（A/D 正常）。三处均为一行级修正，其余保持 Grok 原样。",
+        "en": "Built locally with the Grok Build TUI; fixed build (3 lines changed). Bug 1: line 82 const WORLD_SEED = 0xAETHER — T/H/R are not hex digits, so the whole script threw a SyntaxError at parse time; before the fix the screen was pure black with only HTML text. Bug 2: the atlas is drawn in the top canvas rows with top-left-origin UVs but no flipY=false, so every face sampled the undrawn black region; before the fix nearby terrain rendered solid black. Bug 3: the forward vector already points where the camera looks, but W subtracted and S added — W walked backward (A/D were fine). One line each; everything else is Grok as-is."
+      }
+    }
+  }
+}