feat(v3): restructure project + add complete frontend

- Restructure: move backend from new_project/ to backend/
- Add full React/TypeScript frontend (37 pages, 17 services, 16 type defs, 11 query hooks)
- Add docs/ with SRS specs, user stories, and workflow documentation
- Update .gitignore for new directory layout

Workflows implemented:
  WF1 User Signup, WF2 Placement Test, WF3 Exam Configuration,
  WF4 General English Exam, WF5 Course Generation,
  WF6 Entity Student Onboarding, AI Course Generation,
  Adaptive Learning Engine UI, White-Label Branding, Score Release

Made-with: Cursor

frontend/src/pages/Index.tsx

@@ -0,0 +1,14 @@
+// Update this page (the content is just a fallback if you fail to update the page)
+
+const Index = () => {
+  return (
+    <div className="flex min-h-screen items-center justify-center bg-background">
+      <div className="text-center">
+        <h1 className="mb-4 text-4xl font-bold">Welcome to Your Blank App</h1>
+        <p className="text-xl text-muted-foreground">Start building your amazing project here!</p>
+      </div>
+    </div>
+  );
+};
+
+export default Index;