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

src/pages/student/SubjectSelection.tsx

@@ -0,0 +1,86 @@
+import { useNavigate } from "react-router-dom";
+import { Card, CardContent, CardHeader, CardTitle, CardDescription } from "@/components/ui/card";
+import { Button } from "@/components/ui/button";
+import { Progress } from "@/components/ui/progress";
+import { BookOpen, ArrowRight } from "lucide-react";
+import { useSubjects, useProficiencySummary } from "@/hooks/queries";
+
+export default function SubjectSelection() {
+  const navigate = useNavigate();
+  const { data: subjects = [], isLoading: ls } = useSubjects();
+  const { data: summaries = [], isLoading: lp } = useProficiencySummary();
+
+  if (ls || lp) return <div className="flex items-center justify-center min-h-[400px]"><div className="animate-spin rounded-full h-8 w-8 border-b-2 border-primary" /></div>;
+
+  const getSummary = (subjectId: number) => summaries.find(s => s.subject_id === subjectId);
+
+  return (
+    <div className="space-y-6">
+      <div>
+        <h1 className="text-2xl font-bold">My Subjects</h1>
+        <p className="text-muted-foreground">Select a subject to view your progress or start a diagnostic assessment.</p>
+      </div>
+
+      <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
+        {subjects.map((subject) => {
+          const summary = getSummary(subject.id);
+          const mastery = summary?.overall_mastery ?? 0;
+          const hasTaken = !!summary;
+
+          return (
+            <Card key={subject.id} className="hover:shadow-md transition-shadow">
+              <CardHeader>
+                <div className="flex items-center gap-3">
+                  <div className="h-10 w-10 rounded-lg bg-primary/10 flex items-center justify-center">
+                    <BookOpen className="h-5 w-5 text-primary" />
+                  </div>
+                  <div>
+                    <CardTitle className="text-lg">{subject.name}</CardTitle>
+                    <CardDescription>{subject.code}</CardDescription>
+                  </div>
+                </div>
+              </CardHeader>
+              <CardContent className="space-y-4">
+                {hasTaken ? (
+                  <>
+                    <div className="space-y-2">
+                      <div className="flex justify-between text-sm">
+                        <span className="text-muted-foreground">Overall Mastery</span>
+                        <span className="font-medium">{Math.round(mastery)}%</span>
+                      </div>
+                      <Progress value={mastery} className="h-2" />
+                    </div>
+                    <div className="flex items-center justify-between text-sm text-muted-foreground">
+                      <span>{summary?.topics_mastered ?? 0} / {summary?.topics_total ?? 0} topics mastered</span>
+                    </div>
+                    <div className="flex gap-2">
+                      <Button variant="outline" size="sm" className="flex-1" onClick={() => navigate(`/student/proficiency/${subject.id}`)}>
+                        View Profile
+                      </Button>
+                      <Button size="sm" className="flex-1" onClick={() => navigate(`/student/plan/${subject.id}`)}>
+                        Learning Plan <ArrowRight className="ml-1 h-3 w-3" />
+                      </Button>
+                    </div>
+                  </>
+                ) : (
+                  <>
+                    <p className="text-sm text-muted-foreground">Take a diagnostic assessment to discover your proficiency level and get a personalized learning plan.</p>
+                    <Button className="w-full" onClick={() => navigate(`/student/diagnostic/${subject.id}`)}>
+                      Start Diagnostic <ArrowRight className="ml-1 h-4 w-4" />
+                    </Button>
+                  </>
+                )}
+              </CardContent>
+            </Card>
+          );
+        })}
+        {subjects.length === 0 && (
+          <div className="col-span-full text-center py-12 text-muted-foreground">
+            <BookOpen className="h-12 w-12 mx-auto mb-3 opacity-40" />
+            <p>No subjects available yet.</p>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}