feat(mockups): slot 13 curtain call; allow three.js in 13

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/PERMISSIONS.md

@@ -22,7 +22,7 @@ or `AGENTS.md` Commands.
 | `bun install --frozen-lockfile` | worked (no changes) |
 | `bun test` | worked — 34 pass, 0 fail, 3 files |
 | `bun test tests/data.test.ts` | worked — 10 pass |
-| `bun test -t "registry has 12"` | worked — 1 pass |
+| `bun test -t "registry has 13"` | worked — 1 pass |
 | `bun run typecheck` | worked (`tsc --noEmit`, exit 0) |
 | `bun run build` | worked — `dist/server.js` + hashed page assets |
 | `bun run dev` (`PORT=3113`) | worked — `/` and all mockup routes 200, no-slash form 302 |