- Add src/i18n/lang.ts for URL/query/storage language detection, runtime state, and language switcher URL generation preserving query parameters
- Expand scripts/pack-canonical-tbl.ts and regenerate src/data/canonical-tbl-strings.ts with 3,721 ENG and 3,374 CHI 1.13c .tbl entries (UI, monsters, SuperUniques, levels, skills, items)
- Add completedEn speech strings for Act II Quest 2 and Act IV Quest 2 in src/data/canonical-quest-data.ts
- Add index.html bilingual entry portal, acts-zh.html (CHI), acts-en.html (ENG), and language switcher in acts.html; configure multi-page rollup inputs in vite.config.ts
- Localize all 15 UI/game modules (level-names-zh, character-sheet, control-bar, globes, ground-items, ground-labels, item-bridge, inventory, skill-tree-panel, hotkeys, npc-table, world-panels, monsters, hud-manager, act-scene) for authentic CHI and zero-CJK ENG modes
- Add tests/issue-503-bilingual-parity.test.ts and scripts/verify-issue-503-browser.ts
TAG=agy
CONV=5016e6fd-4af8-421f-ae4b-6d443a0a102a
