feat: redesign Exams List page to show submitted custom exams

- Added Custom Exams tab showing all exams from Generation page
- Displays title, module badges, duration, and status
- Added Create Exam button
- Kept Exam Sessions tab for institutional sessions
- Search filters across exams

Made-with: Cursor

node_modules/autoprefixer/lib/hacks/placeholder.js

@@ -0,0 +1,33 @@
+let Selector = require('../selector')
+
+class Placeholder extends Selector {
+  /**
+   * Add old mozilla to possible prefixes
+   */
+  possible() {
+    return super.possible().concat(['-moz- old', '-ms- old'])
+  }
+
+  /**
+   * Return different selectors depend on prefix
+   */
+  prefixed(prefix) {
+    if (prefix === '-webkit-') {
+      return '::-webkit-input-placeholder'
+    }
+    if (prefix === '-ms-') {
+      return '::-ms-input-placeholder'
+    }
+    if (prefix === '-ms- old') {
+      return ':-ms-input-placeholder'
+    }
+    if (prefix === '-moz- old') {
+      return ':-moz-placeholder'
+    }
+    return `::${prefix}placeholder`
+  }
+}
+
+Placeholder.names = ['::placeholder']
+
+module.exports = Placeholder