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/components/cards.css

@@ -198,7 +198,6 @@
 
 .files-grid-view .file-item .file-icon > i,
 .files-grid-view .file-item .file-icon > svg {
-    /* biome-ignore lint/complexity/noImportantStyles: <explanation> */
     position: absolute;
     top: 5px;
     width: 60px;