[shobhamerabacha-star]

Summary

Closes #80

Prepares ModelTrace for internationalization by introducing a stable message catalogue architecture, adopting Next.js i18n routing (English-only active locale), replacing ambiguous hand-formatted numbers/currencies/dates with standard Intl formatters, and length-proofing responsive layouts for text expansion (such as German and Finnish).

Key Changes

• Message Catalogue & Translation Engine (lib/i18n/):
  • lib/i18n/config.ts: Configured DEFAULT_LOCALE = 'en', SUPPORTED_LOCALES = ['en'], and bidirectional text direction detection (getLocaleDirection) with RTL readiness (Arabic, Hebrew, Persian, Urdu).
  • lib/i18n/messages/en.ts: Structured, canonical message catalogue covering common, home, operators, compliance, and errors.
  • lib/i18n/index.ts: Type-safe dot-notated lookup t(key, params?) with variable interpolation and resilient fallback.
• Next.js i18n Routing Middleware (middleware.ts):
  • Implemented Next.js request middleware resolving locale and injecting x-locale, Content-Language, and x-direction headers.
• Standardized Intl Formatting (lib/i18n/formatters.ts):
  • formatNumber, formatCurrency (USD/EUR/XLM), formatPercent, formatCompactNumber (e.g. 1.2M), formatDate, formatDateTime, and formatTime preventing financial figure misinterpretations across regions.
• Component & View Integration:
  • app/layout.tsx: Configured root <html lang="en" dir="ltr">.
  • app/page.tsx: Wired landing headline, lead, CTAs, stats, and pillars to message catalogue.
  • components/site-footer.tsx: Wired footer text and repository link label to message catalogue.
  • app/operators/components/SettlementsPanel.tsx: Replaced ad-hoc number formatting with formatCompactNumber and localized labels.
  • app/operators/components/QuotasPanel.tsx: Formatted used/limit quotas via formatNumber and formatPercent.
  • app/operators/components/AttestationsPanel.tsx: Formatted timestamps and token counts via formatTime and formatNumber.
• Layout Length-Proofing & RTL Foundations (app/globals.css):
  • Added overflow-wrap: break-word, hyphens: auto, and flex-wrap wrapping for buttons, pills, cards, and tables ensuring layouts remain stable when strings expand 30-50% in languages like German or Finnish.
  • Added [dir="rtl"]: bidirectional alignment and spacing foundations.
• Unit Testing Suite (tests/unit/i18n.test.ts):
  • 14 vitest unit tests validating i18n configuration, RTL detection, message lookup, parameter interpolation, number/currency/percent/compact formatters, date/time formatters, and layout string expansion resilience (+35% text length).

Verification

• npm test: 24/24 test files passed, 150/150 tests passing green (100%).
• npm run lint: 0 ESLint warnings or errors.
• npm run build (next build): Production build compiled and generated all 21 static pages successfully.