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-group.tsx

@@ -0,0 +1,146 @@
+"use client";
+
+import * as React from "react";
+import { cva, type VariantProps } from "class-variance-authority";
+import { cn } from "cn";
+
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Textarea } from "@/components/ui/textarea";
+
+function InputGroup({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="input-group"
+      role="group"
+      className={cn(
+        "group/input-group relative flex h-8 w-full min-w-0 items-center rounded-lg border border-input transition-colors outline-none in-data-[slot=combobox-content]:focus-within:border-inherit in-data-[slot=combobox-content]:focus-within:ring-0 has-disabled:bg-input/50 has-disabled:opacity-50 has-[[data-slot=input-group-control]:focus-visible]:border-ring has-[[data-slot=input-group-control]:focus-visible]:ring-3 has-[[data-slot=input-group-control]:focus-visible]:ring-ring/50 has-[[data-slotLine truncated
+        className
+      )}
+      {...props}
+    />
+  );
+}
+
+const inputGroupAddonVariants = cva(
+  "flex h-auto cursor-text items-center justify-center gap-2 py-1.5 text-sm font-medium text-muted-foreground select-none group-data-[disabled=true]/input-group:opacity-50 [&>kbd]:rounded-[calc(var(--radius)-5px)] [&>svg:not([class*='size-'])]:size-4",
+  {
+    variants: {
+      align: {
+        "inline-start": "order-first pl-2 has-[>button]:ml-[-0.3rem] has-[>kbd]:ml-[-0.15rem]",
+        "inline-end": "order-last pr-2 has-[>button]:mr-[-0.3rem] has-[>kbd]:mr-[-0.15rem]",
+        "block-start":
+          "order-first w-full justify-start px-2.5 pt-2 group-has-[>input]/input-group:pt-2 [.border-b]:pb-2",
+        "block-end":
+          "order-last w-full justify-start px-2.5 pb-2 group-has-[>input]/input-group:pb-2 [.border-t]:pt-2",
+      },
+    },
+    defaultVariants: {
+      align: "inline-start",
+    },
+  }
+);
+
+function InputGroupAddon({
+  className,
+  align = "inline-start",
+  ...props
+}: React.ComponentProps<"div"> & VariantProps<typeof inputGroupAddonVariants>) {
+  return (
+    <div
+      role="group"
+      data-slot="input-group-addon"
+      data-align={align}
+      className={cn(inputGroupAddonVariants({ align }), className)}
+      onClick={(e) => {
+        if ((e.target as HTMLElement).closest("button")) {
+          return;
+        }
+        e.currentTarget.parentElement?.querySelector("input")?.focus();
+      }}
+      {...props}
+    />
+  );
+}
+
+const inputGroupButtonVariants = cva("flex items-center gap-2 text-sm shadow-none", {
+  variants: {
+    size: {
+      xs: "h-6 gap-1 rounded-[calc(var(--radius)-3px)] px-1.5 [&>svg:not([class*='size-'])]:size-3.5",
+      sm: "",
+      "icon-xs": "size-6 rounded-[calc(var(--radius)-3px)] p-0 has-[>svg]:p-0",
+      "icon-sm": "size-8 p-0 has-[>svg]:p-0",
+    },
+  },
+  defaultVariants: {
+    size: "xs",
+  },
+});
+
+function InputGroupButton({
+  className,
+  type = "button",
+  variant = "ghost",
+  size = "xs",
+  ...props
+}: Omit<React.ComponentProps<typeof Button>, "size" | "type"> &
+  VariantProps<typeof inputGroupButtonVariants> & {
+    type?: "button" | "submit" | "reset";
+  }) {
+  return (
+    <Button
+      type={type}
+      data-size={size}
+      variant={variant}
+      className={cn(inputGroupButtonVariants({ size }), className)}
+      {...props}
+    />
+  );
+}
+
+function InputGroupText({ className, ...props }: React.ComponentProps<"span">) {
+  return (
+    <span
+      className={cn(
+        "flex items-center gap-2 text-sm text-muted-foreground [&_svg]:pointer-events-none [&_svg:not([class*='size-'])]:size-4",
+        className
+      )}
+      {...props}
+    />
+  );
+}
+
+function InputGroupInput({ className, ...props }: React.ComponentProps<"input">) {
+  return (
+    <Input
+      data-slot="input-group-control"
+      className={cn(
+        "flex-1 rounded-none border-0 bg-transparent shadow-none ring-0 focus-visible:ring-0 disabled:bg-transparent aria-invalid:ring-0 dark:bg-transparent dark:disabled:bg-transparent",
+        className
+      )}
+      {...props}
+    />
+  );
+}
+
+function InputGroupTextarea({ className, ...props }: React.ComponentProps<"textarea">) {
+  return (
+    <Textarea
+      data-slot="input-group-control"
+      className={cn(
+        "flex-1 resize-none rounded-none border-0 bg-transparent py-2 shadow-none ring-0 focus-visible:ring-0 disabled:bg-transparent aria-invalid:ring-0 dark:bg-transparent dark:disabled:bg-transparent",
+        className
+      )}
+      {...props}
+    />
+  );
+}
+
+export {
+  InputGroup,
+  InputGroupAddon,
+  InputGroupButton,
+  InputGroupText,
+  InputGroupInput,
+  InputGroupTextarea,
+};