fix: change comma-dangle rule to always-multiline per review feedback (#88)

Addresses Gemini review feedback from PR #66 (issue #73).
Changes 'comma-dangle' from 'never' to 'always-multiline' to improve
maintainability — cleaner git diffs and easier line reordering.
Updates admin/js files to comply with the new rule.

Closes #73

.eslintrc.js

@@ -16,7 +16,7 @@ module.exports = {
     sourceType: 'module'
   },
   rules: {
-    'comma-dangle': ['error', 'never'],
+    'comma-dangle': ['error', 'always-multiline'],
     'no-console': 'warn',
     'no-unused-vars': 'warn'
   },