Internationalization (i18n)

[kafkade]

Tracks Phase 5.3 — Internationalization (i18n) from docs/SPEC.md §5.

Goal

Externalize user-facing strings so Kite can be translated, and format numbers/dates per locale.

Scope

• Externalize strings via fluent-rs (or similar) — no hard-coded UI text
• Ship with English as the default; community translations welcome
• Locale-aware number/date formatting
• RTL layout support (future / stretch — track but not required for first pass)

Notes

• Touches every widget in src/ui/widgets/ and the help/menu/dialog overlays.
• Establish a string-catalog layout and a contributor workflow for adding translations (coordinate with Documentation issue Documentation & community #22).