Fix file sharing load speed and move error; misc updates

- Remove recursive directory size calculations (single Seafile API call per list)
- Remove 'Used in this location' usage display
- Fix move using v2 per-type endpoints instead of broken batch endpoint
- Send entry type from frontend for correct move routing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

eslint.config.js

@@ -5,7 +5,18 @@ import reactRefresh from 'eslint-plugin-react-refresh'
 import { defineConfig, globalIgnores } from 'eslint/config'
 
 export default defineConfig([
-  globalIgnores(['dist']),
+  globalIgnores(['dist', '.vercel']),
+  {
+    files: ['api/**/*.js'],
+    languageOptions: {
+      ecmaVersion: 2020,
+      globals: globals.node,
+      sourceType: 'module',
+    },
+    rules: {
+      'no-unused-vars': ['error', { varsIgnorePattern: '^[A-Z_]' }],
+    },
+  },
   {
     files: ['**/*.{js,jsx}'],
     extends: [