feat: implementasi Kodeva - sistem manajemen kursus coding

Fitur lengkap:
- Auth JWT + RBAC (Admin/Teacher) + halaman login
- Shell 3 kolom (left nav, topbar, right rail dashboard)
- CRUD siswa + follow up kanban + status calon/student/ex
- Dashboard: siswa aktif, kehadiran, bar sumber lead, perlu follow up
- Pembayaran prorata per pertemuan (cash/transfer/qris)
- Kelas, enrollment, generate sesi, kehadiran bulk
- Jurnal aktivitas + upload multi-foto
- Raport + placement test (tampil di detail siswa)
- Pengaturan & seed data contoh

Stack: Next.js 16, TypeScript, Tailwind v4, Prisma (SQLite), Recharts, Zod

.env.example

@@ -0,0 +1,8 @@
+DATABASE_URL="file:./dev.db"
+AUTH_SECRET="ganti-dengan-random-32-char"
+AUTH_TRUST_HOST=true
+NEXT_PUBLIC_APP_NAME="Kodeva"
+NEXT_PUBLIC_APP_URL="http://localhost:3000"
+UPLOAD_DIR="./public/uploads"
+MAX_UPLOAD_MB=5
+TZ="Asia/Jakarta"