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/tooltip.tsx

@@ -0,0 +1,53 @@
+"use client";
+
+import { Tooltip as TooltipPrimitive } from "@base-ui/react/tooltip";
+import { cn } from "cn";
+
+function TooltipProvider({ delay = 0, ...props }: TooltipPrimitive.Provider.Props) {
+  return <TooltipPrimitive.Provider data-slot="tooltip-provider" delay={delay} {...props} />;
+}
+
+function Tooltip({ ...props }: TooltipPrimitive.Root.Props) {
+  return <TooltipPrimitive.Root data-slot="tooltip" {...props} />;
+}
+
+function TooltipTrigger({ ...props }: TooltipPrimitive.Trigger.Props) {
+  return <TooltipPrimitive.Trigger data-slot="tooltip-trigger" {...props} />;
+}
+
+function TooltipContent({
+  className,
+  side = "top",
+  sideOffset = 4,
+  align = "center",
+  alignOffset = 0,
+  children,
+  ...props
+}: TooltipPrimitive.Popup.Props &
+  Pick<TooltipPrimitive.Positioner.Props, "align" | "alignOffset" | "side" | "sideOffset">) {
+  return (
+    <TooltipPrimitive.Portal>
+      <TooltipPrimitive.Positioner
+        align={align}
+        alignOffset={alignOffset}
+        side={side}
+        sideOffset={sideOffset}
+        className="isolate z-50"
+      >
+        <TooltipPrimitive.Popup
+          data-slot="tooltip-content"
+          className={cn(
+            "z-50 inline-flex w-fit max-w-xs origin-(--transform-origin) items-center gap-1.5 rounded-md bg-foreground px-3 py-1.5 text-xs text-background has-data-[slot=kbd]:pr-1.5 data-[side=bottom]:slide-in-from-top-2 data-[side=inline-end]:slide-in-from-left-2 data-[side=inline-start]:slide-in-from-right-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 **:data-[slot=kbd]:relative **:data-[slot=kbd]:isolate **:data-[slot=kLine truncated
+            className
+          )}
+          {...props}
+        >
+          {children}
+          <TooltipPrimitive.Arrow className="z-50 size-2.5 translate-y-[calc(-50%-2px)] rotate-45 rounded-[2px] bg-foreground fill-foreground data-[side=bottom]:top-1 data-[side=inline-end]:top-1/2! data-[side=inline-end]:-left-1 data-[side=inline-end]:-translate-y-1/2 data-[side=inline-start]:top-1/2! data-[side=inline-start]:-right-1 data-[side=inline-start]:-translate-y-1/2 data-[side=left]:top-1/2! data-[side=left]:-right-1 data-[side=left]:-translate-y-1/2 data-[side=right]:top-1/2! data-[Line truncated
+        </TooltipPrimitive.Popup>
+      </TooltipPrimitive.Positioner>
+    </TooltipPrimitive.Portal>
+  );
+}
+
+export { Tooltip, TooltipTrigger, TooltipContent, TooltipProvider };