chore: clean up repo for public release

- Remove BMAD framework, IDE configs, dev screenshots, test files,
  internal docs, and backup files
- Rename keep-notes/ to memento-note/
- Update all references from keep-notes to memento-note
- Add Apache 2.0 license with Commons Clause (non-commercial restriction)
- Add clean .gitignore and .env.docker.example

memento-note/lib/i18n/LanguageProvider.tsx

@@ -0,0 +1,113 @@
+'use client'
+
+import { createContext, useContext, useEffect, useState, useCallback, useRef } from 'react'
+import type { ReactNode } from 'react'
+import { SupportedLanguage, loadTranslations, getTranslationValue, Translations } from './load-translations'
+
+// Static imports for SSR-safe initial translations (prevents hydration mismatch)
+import enTranslations from '@/locales/en.json'
+
+type LanguageContextType = {
+  language: SupportedLanguage
+  setLanguage: (lang: SupportedLanguage) => void
+  t: (key: string, params?: Record<string, string | number>) => string
+  translations: Translations
+}
+
+const LanguageContext = createContext<LanguageContextType | undefined>(undefined)
+
+const RTL_LANGUAGES: SupportedLanguage[] = ['ar', 'fa']
+const SUPPORTED_LANGS: SupportedLanguage[] = ['en', 'fr', 'es', 'de', 'fa', 'it', 'pt', 'ru', 'zh', 'ja', 'ko', 'ar', 'hi', 'nl', 'pl']
+
+function updateDocumentDirection(lang: SupportedLanguage) {
+  document.documentElement.lang = lang
+  document.documentElement.dir = RTL_LANGUAGES.includes(lang) ? 'rtl' : 'ltr'
+}
+
+/**
+ * Resolve the actual language to use:
+ * 1. If localStorage has a saved preference, use that (client only)
+ * 2. Otherwise fall back to the server-detected initialLanguage
+ */
+function resolveLanguage(fallback: SupportedLanguage): SupportedLanguage {
+  if (typeof window !== 'undefined') {
+    try {
+      const saved = localStorage.getItem('user-language') as SupportedLanguage
+      if (saved && SUPPORTED_LANGS.includes(saved)) return saved
+    } catch {}
+  }
+  return fallback
+}
+
+export function LanguageProvider({ children, initialLanguage = 'en', initialTranslations }: {
+  children: ReactNode
+  initialLanguage?: SupportedLanguage
+  initialTranslations?: Translations
+}) {
+  // Resolve language synchronously from localStorage BEFORE any effect runs.
+  // This prevents the flash where initialLanguage ('en') overrides RTL.
+  const [language, setLanguageState] = useState<SupportedLanguage>(() => resolveLanguage(initialLanguage))
+
+  // Start with server-provided translations or English fallback
+  const [translations, setTranslations] = useState<Translations>(
+    (initialTranslations || enTranslations) as unknown as Translations
+  )
+  const cacheRef = useRef<Map<SupportedLanguage, Translations>>(new Map())
+  const isFirstRender = useRef(true)
+
+  // Load translations when language changes (with caching)
+  // On first render, skip updateDocumentDirection since the inline script already set it.
+  useEffect(() => {
+    const cached = cacheRef.current.get(language)
+    if (cached) {
+      setTranslations(cached)
+      if (!isFirstRender.current) updateDocumentDirection(language)
+      isFirstRender.current = false
+      return
+    }
+
+    const loadLang = async () => {
+      const loaded = await loadTranslations(language)
+      cacheRef.current.set(language, loaded)
+      setTranslations(loaded)
+      if (!isFirstRender.current) updateDocumentDirection(language)
+      isFirstRender.current = false
+    }
+    loadLang()
+  }, [language])
+
+  const setLanguage = useCallback((lang: SupportedLanguage) => {
+    setLanguageState(lang)
+    localStorage.setItem('user-language', lang)
+    updateDocumentDirection(lang)
+  }, [])
+
+  const t = useCallback((key: string, params?: Record<string, string | number>) => {
+    if (!translations) return key
+
+    let value: any = getTranslationValue(translations, key)
+
+    // Replace parameters like {count}, {percentage}, etc.
+    if (params && typeof value === 'string') {
+      Object.entries(params).forEach(([param, paramValue]) => {
+        value = value.replace(`{${param}}`, String(paramValue))
+      })
+    }
+
+    return typeof value === 'string' ? value : key
+  }, [translations])
+
+  return (
+    <LanguageContext.Provider value={{ language, setLanguage, t, translations }}>
+      {children}
+    </LanguageContext.Provider>
+  )
+}
+
+export function useLanguage() {
+  const context = useContext(LanguageContext)
+  if (context === undefined) {
+    throw new Error('useLanguage must be used within a LanguageProvider')
+  }
+  return context
+}