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/siginfo/test.js

@@ -0,0 +1,16 @@
+var siginfo = require('.')
+var pkg = require('./package.json')
+
+var stop = siginfo(function () {
+  console.dir({
+    version: pkg.version,
+    uptime: process.uptime()
+  })
+})
+
+process.stdout.resume()
+
+setTimeout(function () {
+  stop()
+  process.exit(0)
+}, 2000)