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>

.github/workflows/ci.yml

@@ -0,0 +1,20 @@
+name: CI
+
+on:
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: oven-sh/setup-bun@v2
+      - name: Install dependencies
+        run: bun install
+        working-directory: site
+      - name: Type-check and build
+        run: bun run build
+        working-directory: site