FIX: Complete internationalization for text and code editors

Missing i18n Fixes:
- Replace "Unknown size" with t("fileManager.unknownSize")
- Replace "File is empty" with t("fileManager.fileIsEmpty")
- Replace "Modified:" with t("fileManager.modified")
- Replace "Large File Warning" with t("fileManager.largeFileWarning")
- Replace file size warning message with t("fileManager.largeFileWarningDesc")

Credential Editor i18n:
- Replace "Invalid Key" with t("credentials.invalidKey")
- Replace "Detection Error" with t("credentials.detectionError")
- Replace "Unknown" with t("credentials.unknown")

Translation Additions:
- English: unknownSize, fileIsEmpty, modified, largeFileWarning, largeFileWarningDesc
- English: invalidKey, detectionError, unknown for credentials
- Chinese: corresponding translations for all new keys

Technical Improvements:
- Update formatFileSize function to accept translation function parameter
- Ensure proper translation interpolation for dynamic content

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/ui/Desktop/Apps/Credentials/CredentialEditor.tsx

@@ -315,9 +315,9 @@ export function CredentialEditor({
       "ssh-dss": "DSA (SSH)",
       "rsa-sha2-256": "RSA-SHA2-256",
       "rsa-sha2-512": "RSA-SHA2-512",
-      invalid: "Invalid Key",
-      error: "Detection Error",
-      unknown: "Unknown",
+      invalid: t("credentials.invalidKey"),
+      error: t("credentials.detectionError"),
+      unknown: t("credentials.unknown"),
     };
     return keyTypeMap[keyType] || keyType;
   };