feat: Add file color coding in file manager

- Files: blue (text-blue-400)
- Folders: red (text-red-400)
- Symlinks: green (text-green-400)
- Add toggle in User Profile settings
- Store preference in localStorage
- Support i18n (en, zh)
- Can be disabled via settings
- Matches dark theme color scheme

src/locales/en/translation.json

@@ -1479,6 +1479,8 @@
     "local": "Local",
     "external": "External (OIDC)",
     "selectPreferredLanguage": "Select your preferred language for the interface",
+    "fileColorCoding": "File Color Coding",
+    "fileColorCodingDesc": "Color-code files by type: folders (red), files (blue), symlinks (green)",
     "currentPassword": "Current Password",
     "passwordChangedSuccess": "Password changed successfully! Please log in again.",
     "failedToChangePassword": "Failed to change password. Please check your current password and try again."