Add Next translation static text foundation

[hta218]

Summary

• add Next static-text translation store/provider/hooks (useTranslation, TranslationProvider) with deprecated ThemeText aliases
• wire root/provider/renderer/runtime so Builder static-text RPC can update internal.translationStore / internal.themeTextStore
• preserve merchantOverrides, schema staticContent, and clear stale overrides on reused runtimes

Verification

• pnpm --filter @weaverse/next test -- __tests__/next-adapter.test.tsx __tests__/next-server.test.tsx — 5 files, 107 tests passed
• pnpm --filter @weaverse/next typecheck — passed
• pnpm --filter @weaverse/next build — passed
• pnpm exec biome check packages/next/src packages/next/__tests__ packages/next/README.md --diagnostic-level=error — passed
• git diff --check — passed
• autoreview-copilot — clean