feat: 擴展 i18n 支援 65 種語言 + 完整文件系統

🌐 國際化 (i18n)
- 從 5 種語言擴展到 65 種語言支援
- 新增：歐洲語系 (de, fr, es, it, pt, ru, nl, pl, tr, uk, cs, sv, da, fi, no, el, hu, ro, bg, hr, sk, sl, lt, lv, et, is, ga, cy, mt, mk, sq, ca, eu, gl, sr)
- 新增：中東語系 (ar, he, fa)
- 新增：南亞語系 (hi, bn, ta, te, mr, gu, kn, ml, ne, si)
- 新增：東南亞語系 (th, vi, id, ms, fil, my, km, lo)
- 新增：非洲語系 (af, sw, am, zu)
- 完整翻譯所有 UI 文字

📖 文件系統
- 重構 README.md 為入口型首頁
- 新增 docs/getting-started.md - 快速入門指南
- 新增 docs/docker.md - Docker 部署指南
- 新增 docs/environment-variables.md - 環境變數說明
- 新增 docs/url-id-and-storage.md - 儲存結構說明
- 新增 docs/advanced-usage.md - 進階使用指南
- 更新 docs/i18n.md - 65 種語言清單

✅ 建構驗證
- TypeScript 編譯通過
- Docker 建構通過

src/locales/sv.json

@@ -0,0 +1,106 @@
+{
+  "common": {
+    "appName": "ConvertX-CN",
+    "poweredBy": "Drivs av",
+    "version": "v{version}",
+    "loading": "Laddar...",
+    "error": "Fel",
+    "success": "Lyckades",
+    "confirm": "Bekräfta",
+    "cancel": "Avbryt",
+    "close": "Stäng",
+    "save": "Spara",
+    "delete": "Ta bort",
+    "remove": "Ta bort",
+    "download": "Ladda ner",
+    "upload": "Ladda upp",
+    "submit": "Skicka",
+    "back": "Tillbaka",
+    "next": "Nästa",
+    "yes": "Ja",
+    "no": "Nej"
+  },
+  "nav": {
+    "history": "Historik",
+    "account": "Konto",
+    "logout": "Logga ut",
+    "login": "Logga in",
+    "register": "Registrera",
+    "language": "Språk"
+  },
+  "convert": {
+    "title": "Konvertera",
+    "titleWithType": "Konvertera .{fileType}",
+    "chooseFile": "Välj en fil",
+    "orDragHere": "eller dra den hit",
+    "searchConversions": "Sök konverteringar",
+    "convertTo": "Konvertera till",
+    "convertButton": "Konvertera",
+    "uploading": "Laddar upp...",
+    "processing": "Bearbetar..."
+  },
+  "results": {
+    "title": "Resultat",
+    "convertedFileName": "Konverterat filnamn",
+    "status": "Status",
+    "actions": "Åtgärder",
+    "downloadAll": "Alla",
+    "downloadTar": "Tar",
+    "deleteJob": "Ta bort",
+    "noFiles": "Inga filer konverterade än.",
+    "statusPending": "Väntar",
+    "statusCompleted": "Slutförd",
+    "statusFailed": "Misslyckades"
+  },
+  "history": {
+    "title": "Resultat",
+    "time": "Tid",
+    "files": "Filer",
+    "filesDone": "Färdiga filer",
+    "status": "Status",
+    "actions": "Åtgärder",
+    "expandDetails": "Expandera detaljer",
+    "detailedFileInfo": "Detaljerad filinformation:",
+    "deleteSelected": "Ta bort valda",
+    "selectAll": "Välj alla",
+    "confirmDelete": "Är du säker på att du vill ta bort {count} jobb? Denna åtgärd kan inte ångras.",
+    "deleteSuccess": "Lyckades ta bort {deleted} jobb.",
+    "deleteFailed": "Kunde inte ta bort {failed} jobb.",
+    "deleteError": "Ett fel uppstod när jobb skulle tas bort. Försök igen."
+  },
+  "auth": {
+    "email": "E-post",
+    "password": "Lösenord",
+    "currentPassword": "Nuvarande lösenord",
+    "newPassword": "Lösenord (lämna tomt för att inte ändra)",
+    "loginButton": "Logga in",
+    "registerButton": "Registrera",
+    "updateButton": "Uppdatera",
+    "createAccount": "Skapa konto",
+    "invalidCredentials": "Ogiltiga inloggningsuppgifter.",
+    "emailInUse": "E-postadressen används redan.",
+    "unauthorized": "Ej auktoriserad",
+    "cookiesRequired": "Cookies måste vara aktiverade för att använda denna app.",
+    "noCookies": "Ingen autentiseringscookie, kanske din webbläsare blockerar cookies."
+  },
+  "setup": {
+    "welcome": "Välkommen till ConvertX-CN!",
+    "createYourAccount": "Skapa ditt konto",
+    "reportIssues": "Rapportera problem på",
+    "github": "GitHub"
+  },
+  "errors": {
+    "jobNotFound": "Jobb hittades inte.",
+    "fileNotFound": "Fil hittades inte.",
+    "uploadFailed": "Uppladdning misslyckades.",
+    "conversionFailed": "Konvertering misslyckades.",
+    "serverError": "Serverfel."
+  },
+  "upload": {
+    "success": "Filerna laddades upp framgångsrikt.",
+    "dragDrop": "Släpp filer här"
+  },
+  "file": {
+    "size": "{size} kB"
+  }
+}