Add runtime atlas residency and intermission flow

[agustin-littlehat]

Summary

• add PVS-aware world atlas residency/debug instrumentation updates
• add Quake-style intermission UI, level stats, and advance handling
• fix weapon view-punch camera origin reapplication during shooting

Validation

• git diff --cached --check
• pnpm test
• pnpm build

Local-only note

• left uncommitted: src/prepare/assets.mjs enemy alias render scale 8 -> 4