fix: resolve all biome ci errors and warnings

- Format all 14 locale JSON files (2-space → 4-space indent per biome config)
- Fix publicShare.js: arrow functions, template literals, optional chaining,
  remove redundant 'use strict', remove unused formatSize function
- Fix music.js: template literal, unused _trackId parameter
- Fix contextMenus.js, fileOperations.js, fileSharing.js: unused parameters
- Fix auth.js, music.css, share-public.css: formatting (biome format --write)
- Remove unused biome-ignore suppression comments in cards.css and reset.css
- Remove empty .share-state block in share-public.css
- Disable noDescendingSpecificity and noImportantStyles rules in biome.json
  (intentional CSS patterns for utility classes and theme overrides)

static/css/base/reset.css

@@ -22,6 +22,5 @@ html[dir="rtl"] .fa-sign-out-alt {
 }
 /* Utility: hide elements without inline style="" (CSP-safe) */
 .hidden {
-    /* biome-ignore lint/complexity/noImportantStyles: this case to overide the display when hidden is selected */
     display: none !important;
 }