web-app-launcher/plans/phase-2-enhanced-features/phase-3-localization.md

Phase 3: Localization (EN/RU)

Status: ⬜ Not Started Parent plan: PLAN.md Domain: fullstack

Objective

Add internationalization (i18n) support with English and Russian locales. All UI strings should be translatable. Users can switch language in settings or header.

Tasks

• Task 1: Install paraglide-sveltekit (or svelte-i18n) — choose the best Svelte 5 compatible i18n library
• Task 2: Create locale files: src/lib/i18n/en.json and src/lib/i18n/ru.json
• Task 3: Create src/lib/i18n/index.ts — i18n setup, locale detection, switcher
• Task 4: Create src/lib/components/layout/LanguageSwitcher.svelte — language toggle (EN/RU) in header
• Task 5: Extract all hardcoded strings from layout components (Sidebar, Header, MainLayout)
• Task 6: Extract all hardcoded strings from auth pages (login, register, logout)
• Task 7: Extract all hardcoded strings from board/section/widget components
• Task 8: Extract all hardcoded strings from app components (AppCard, AppForm, AppIconPicker, etc.)
• Task 9: Extract all hardcoded strings from admin pages (users, groups, settings)
• Task 10: Extract all hardcoded strings from search components
• Task 11: Add locale preference to user settings (stored in localStorage + optional DB field)
• Task 12: Add language setting to admin SystemSettings (default locale)
• Task 13: Translate all strings to Russian

Files to Modify/Create

• src/lib/i18n/en.json — NEW
• src/lib/i18n/ru.json — NEW
• src/lib/i18n/index.ts — NEW
• src/lib/components/layout/LanguageSwitcher.svelte — NEW
• src/lib/components/layout/Header.svelte — MODIFY
• src/routes/login/+page.svelte — MODIFY
• src/routes/register/+page.svelte — MODIFY
• src/routes/boards/*.svelte — MODIFY
• src/routes/apps/+page.svelte — MODIFY
• src/routes/admin/**/*.svelte — MODIFY
• src/lib/components/**/*.svelte — MODIFY (all UI components)

Acceptance Criteria

• All user-visible strings are translatable (no hardcoded text in components)
• English and Russian translations are complete
• Language switcher in the header toggles between EN/RU
• Locale preference persists across sessions (localStorage)
• Default locale is configurable in admin settings
• Date/number formatting respects locale

Notes

• Use a flat key structure: { "nav.boards": "Boards", "nav.apps": "Apps", ... }
• Keep translation keys semantic and grouped by feature
• Validation error messages from Zod should also be translatable
• ⚠️ Big Bang: string extraction touches many files

Review Checklist

• All tasks completed
• Code follows project conventions
• No unintended side effects
• Build passes
• Tests pass (new + existing)

Handoff to Next Phase