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/native-select.tsx

@@ -0,0 +1,54 @@
+import * as React from "react";
+import { cn } from "cn";
+import { ChevronDownIcon } from "lucide-react";
+
+type NativeSelectProps = Omit<React.ComponentProps<"select">, "size"> & {
+  size?: "sm" | "default";
+};
+
+function NativeSelect({ className, size = "default", ...props }: NativeSelectProps) {
+  return (
+    <div
+      className={cn(
+        "group/native-select relative w-fit has-[select:disabled]:opacity-50",
+        className
+      )}
+      data-slot="native-select-wrapper"
+      data-size={size}
+    >
+      <select
+        data-slot="native-select"
+        data-size={size}
+        className="h-8 w-full min-w-0 appearance-none rounded-lg border border-input bg-transparent py-1 pr-8 pl-2.5 text-sm transition-colors outline-none select-none selection:bg-primary selection:text-primary-foreground placeholder:text-muted-foreground focus-visible:border-ring focus-visible:ring-3 focus-visible:ring-ring/50 disabled:pointer-events-none disabled:cursor-not-allowed aria-invalid:border-destructive aria-invalid:ring-3 aria-invalid:ring-destructive/20 data-[size=sm]:h-7 data-[sLine truncated
+        {...props}
+      />
+      <ChevronDownIcon
+        className="pointer-events-none absolute top-1/2 right-2.5 size-4 -translate-y-1/2 text-muted-foreground select-none"
+        aria-hidden="true"
+        data-slot="native-select-icon"
+      />
+    </div>
+  );
+}
+
+function NativeSelectOption({ className, ...props }: React.ComponentProps<"option">) {
+  return (
+    <option
+      data-slot="native-select-option"
+      className={cn("bg-[Canvas] text-[CanvasText]", className)}
+      {...props}
+    />
+  );
+}
+
+function NativeSelectOptGroup({ className, ...props }: React.ComponentProps<"optgroup">) {
+  return (
+    <optgroup
+      data-slot="native-select-optgroup"
+      className={cn("bg-[Canvas] text-[CanvasText]", className)}
+      {...props}
+    />
+  );
+}
+
+export { NativeSelect, NativeSelectOptGroup, NativeSelectOption };