feat: setup full Next.js toolchain and core dependencies

- Add runtime deps: react-query, react-hook-form+zod, zustand, ky, openapi-fetch,
  better-auth, react-markdown, shiki, recharts, next-themes, nuqs, sonner, cmdk,
  vaul, embla-carousel-react, motion, date-fns, tailwind-merge, clsx, cva
- Add dev tooling: vitest, testing-library, playwright, prettier(+tailwind plugin),
  husky, lint-staged, jsdom
- Wire providers (QueryClient, Theme, NuqsAdapter, Tooltip, Sonner) into layout
- Add vitest/playwright/prettier configs + lint-staged pre-commit hook
- Add lib/query-client + lib/http (ky) helpers and sample unit test
- Fix react-hooks/set-state-in-effect lint errors (use-mobile useSyncExternalStore,
  carousel async init)
- Remove committed Next-generated types/ duplicates (regenerated under .next/types)

components/ui/input-otp.tsx

@@ -0,0 +1,85 @@
+"use client";
+
+import * as React from "react";
+import { cn } from "cn";
+import { OTPInput, OTPInputContext } from "input-otp";
+import { MinusIcon } from "lucide-react";
+
+function InputOTP({
+  className,
+  containerClassName,
+  ...props
+}: React.ComponentProps<typeof OTPInput> & {
+  containerClassName?: string;
+}) {
+  return (
+    <OTPInput
+      data-slot="input-otp"
+      containerClassName={cn(
+        "cn-input-otp flex items-center has-disabled:opacity-50",
+        containerClassName
+      )}
+      spellCheck={false}
+      className={cn("disabled:cursor-not-allowed", className)}
+      {...props}
+    />
+  );
+}
+
+function InputOTPGroup({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="input-otp-group"
+      className={cn(
+        "flex items-center rounded-lg has-aria-invalid:border-destructive has-aria-invalid:ring-3 has-aria-invalid:ring-destructive/20 dark:has-aria-invalid:ring-destructive/40",
+        className
+      )}
+      {...props}
+    />
+  );
+}
+
+function InputOTPSlot({
+  index,
+  className,
+  ...props
+}: React.ComponentProps<"div"> & {
+  index: number;
+}) {
+  const inputOTPContext = React.useContext(OTPInputContext);
+  const { char, hasFakeCaret, isActive } = inputOTPContext?.slots[index] ?? {};
+
+  return (
+    <div
+      data-slot="input-otp-slot"
+      data-active={isActive}
+      className={cn(
+        "relative flex size-8 items-center justify-center border-y border-r border-input text-sm transition-all outline-none first:rounded-l-lg first:border-l last:rounded-r-lg aria-invalid:border-destructive data-[active=true]:z-10 data-[active=true]:border-ring data-[active=true]:ring-3 data-[active=true]:ring-ring/50 data-[active=true]:aria-invalid:border-destructive data-[active=true]:aria-invalid:ring-destructive/20 dark:bg-input/30 dark:data-[active=true]:aria-invalid:ring-destructive/40"Line truncated
+        className
+      )}
+      {...props}
+    >
+      {char}
+      {hasFakeCaret && (
+        <div className="pointer-events-none absolute inset-0 flex items-center justify-center">
+          <div className="h-4 w-px animate-caret-blink bg-foreground duration-1000" />
+        </div>
+      )}
+    </div>
+  );
+}
+
+function InputOTPSeparator({ ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="input-otp-separator"
+      className="flex items-center [&_svg:not([class*='size-'])]:size-4"
+      role="separator"
+      {...props}
+    >
+      <MinusIcon />
+    </div>
+  );
+}
+
+export { InputOTP, InputOTPGroup, InputOTPSlot, InputOTPSeparator };