feat: initial frontend codebase — EnCoach v3

React 18 + TypeScript + Vite 5 + Tailwind CSS + shadcn/ui frontend:
- Multi-role auth: student, teacher, admin, corporate, agent, developer
- Student portal: dashboard, courses, adaptive learning, exams, placement
- Teacher portal: courses, assignments, grading, attendance, AI workbench
- Admin portal: 60+ management pages (LMS, exams, users, entities, AI)
- AI-powered features: study coach, generation page, gap analysis, TTS
- Exam system: session, auto-save, results, grading queue
- Full IELTS workflow: reading/listening/writing/speaking modules

Made-with: Cursor

.env.example

@@ -0,0 +1,3 @@
+# Dev: use /api with Vite proxy (see vite.config.ts). Production: full URL, e.g. https://your-odoo/api
+VITE_API_BASE_URL=/api
+VITE_APP_NAME=EnCoach