Show renderer stats with I, link home from the pause screen, new favicon

[valuecodes]

What

• Part 4/5 of Post-MVP additions: a renderer.info readout to measure before area unloading.
• I (or ?stats=1) shows draws · tris · geo · tex · areas · ms/frame bottom right, sampled every 500 ms with every post-processing pass counted, through a feed so only that line re-renders.
• Measured on ?code=self: draws and triangles depend on the view (182 built areas draw what 1 does), GPU geometries and textures grow only with areas seen, and the JS heap grows about 1.4 MB per built area (43 → 301 MB). These numbers will set the unloading budget.
• The pause screen gets a ← Home link back to the landing page, and the favicon becomes a yellow backrooms wall with a dark doorway instead of the template icon.

How to test

pnpm typecheck
pnpm lint
pnpm knip
pnpm test
pnpm build
pnpm --filter web dev  # open /?code=self&stats=1, press I; press Esc for the Home link

Security review

No security-impacting changes.

🤖 Generated with Claude Code

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[chatgpt-codex-connector]

Codex Review Summary

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-14T12:07:25.328893Z	6aaf6be	PR opened

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Reviewed commit: 6aaf6be8bf

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