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

src/components/ui/form.tsx

@@ -0,0 +1,57 @@
+import type { InputHTMLAttributes, LabelHTMLAttributes, SelectHTMLAttributes, TextareaHTMLAttributes } from "react";
+import { cn } from "@/lib/utils";
+
+export function Label({ className, ...props }: LabelHTMLAttributes<HTMLLabelElement>) {
+  return <label className={cn("mb-1.5 block text-[13px] font-medium text-ink-700", className)} {...props} />;
+}
+
+const baseField =
+  "w-full rounded-[12px] border border-ink-300 bg-surface px-3 text-sm text-ink-900 placeholder:text-ink-500 transition-colors focus:border-brand-500 focus:outline-none focus:ring-[3px] focus:ring-brand-500/25 disabled:bg-ink-100";
+
+export function Input({ className, ...props }: InputHTMLAttributes<HTMLInputElement>) {
+  return <input className={cn(baseField, "h-10", className)} {...props} />;
+}
+
+export function Textarea({ className, ...props }: TextareaHTMLAttributes<HTMLTextAreaElement>) {
+  return <textarea className={cn(baseField, "min-h-[88px] py-2.5", className)} {...props} />;
+}
+
+export function Select({ className, children, ...props }: SelectHTMLAttributes<HTMLSelectElement>) {
+  return (
+    <select className={cn(baseField, "h-10 appearance-none bg-[length:16px] pr-9", className)} {...props}>
+      {children}
+    </select>
+  );
+}
+
+export function Field({
+  label,
+  required,
+  hint,
+  error,
+  children,
+  className,
+}: {
+  label?: string;
+  required?: boolean;
+  hint?: string;
+  error?: string;
+  children: React.ReactNode;
+  className?: string;
+}) {
+  return (
+    <div className={className}>
+      {label ? (
+        <Label>
+          {label} {required ? <span className="text-danger-500">*</span> : null}
+        </Label>
+      ) : null}
+      {children}
+      {error ? (
+        <p className="mt-1 text-[12px] text-danger-500">{error}</p>
+      ) : hint ? (
+        <p className="mt-1 text-[12px] text-ink-500">{hint}</p>
+      ) : null}
+    </div>
+  );
+}