Feat: 세션 유지 컴포넌트 추가 및 주석 디자인 다크테마 적용

components/form-message.tsx

@@ -1,16 +1,23 @@
+/**
+ * @file components/form-message.tsx
+ * @description 폼 제출 결과(성공/에러) 메시지를 표시하는 컴포넌트
+ * @remarks
+ * - [레이어] Components/UI/Feedback
+ * - [기능] URL 쿼리 파라미터(`message`)를 감지하여 표시 후 URL 정리
+ * - [UX] 메시지 확인 후 새로고침 시 메시지가 남지 않도록 히스토리 정리 (History API)
+ */
+
 "use client";
 
 import { useEffect } from "react";
-import { usePathname, useRouter, useSearchParams } from "next/navigation";
+import { usePathname, useSearchParams } from "next/navigation";
 
 /**
- * [FormMessage 컴포넌트]
- * - 로그인/회원가입 실패 메시지를 보여줍니다.
- * - [UX 개선] 메시지가 보인 후, URL에서 ?message=... 부분을 지워서
- *   새로고침 시 메시지가 다시 뜨지 않도록 합니다.
+ * 폼 메시지 컴포넌트
+ * @param message 표시할 메시지 텍스트
+ * @returns 메시지 박스 또는 null
  */
 export default function FormMessage({ message }: { message: string }) {
-  const router = useRouter();
   const pathname = usePathname();
   const searchParams = useSearchParams();
 

components/theme-provider.tsx

@@ -0,0 +1,25 @@
+/**
+ * @file components/theme-provider.tsx
+ * @description next-themes 라이브러리를 사용한 테마 제공자 (Wrapper)
+ * @remarks
+ * - [레이어] Infrastructure/Provider
+ * - [역할] 앱 전역에 테마 컨텍스트 주입 (Light/Dark 모드 지원)
+ * - [연관 파일] layout.tsx (사용처)
+ */
+
+"use client";
+
+import * as React from "react";
+import { ThemeProvider as NextThemesProvider } from "next-themes";
+
+/**
+ * ThemeProvider 컴포넌트
+ * @param props next-themes Provider props
+ * @returns NextThemesProvider 래퍼
+ */
+export function ThemeProvider({
+  children,
+  ...props
+}: React.ComponentProps<typeof NextThemesProvider>) {
+  return <NextThemesProvider {...props}>{children}</NextThemesProvider>;
+}

components/theme-toggle.tsx

@@ -0,0 +1,59 @@
+/**
+ * @file components/theme-toggle.tsx
+ * @description 라이트/다크/시스템 테마 전환 토글 버튼
+ * @remarks
+ * - [레이어] Components/UI
+ * - [사용자 행동] 버튼 클릭 -> 드롭다운 메뉴 -> 테마 선택 -> 즉시 반영
+ * - [연관 파일] theme-provider.tsx (next-themes)
+ */
+
+"use client";
+
+import * as React from "react";
+import { Moon, Sun } from "lucide-react";
+import { useTheme } from "next-themes";
+
+import { Button } from "@/components/ui/button";
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu";
+
+/**
+ * 테마 토글 컴포넌트
+ * @remarks next-themes의 useTheme 훅 사용
+ * @returns Dropdown 메뉴 형태의 테마 선택기
+ */
+export function ThemeToggle() {
+  const { setTheme } = useTheme();
+
+  return (
+    <DropdownMenu modal={false}>
+      {/* ========== 트리거 버튼 ========== */}
+      <DropdownMenuTrigger asChild>
+        <Button variant="ghost" size="icon">
+          {/* 라이트 모드 아이콘 (회전 애니메이션) */}
+          <Sun className="h-[1.2rem] w-[1.2rem] rotate-0 scale-100 transition-all dark:-rotate-90 dark:scale-0" />
+          {/* 다크 모드 아이콘 (회전 애니메이션) */}
+          <Moon className="absolute h-[1.2rem] w-[1.2rem] rotate-90 scale-0 transition-all dark:rotate-0 dark:scale-100" />
+          <span className="sr-only">Toggle theme</span>
+        </Button>
+      </DropdownMenuTrigger>
+
+      {/* ========== 메뉴 컨텐츠 (우측 정렬) ========== */}
+      <DropdownMenuContent align="end">
+        <DropdownMenuItem onClick={() => setTheme("light")}>
+          Light
+        </DropdownMenuItem>
+        <DropdownMenuItem onClick={() => setTheme("dark")}>
+          Dark
+        </DropdownMenuItem>
+        <DropdownMenuItem onClick={() => setTheme("system")}>
+          System
+        </DropdownMenuItem>
+      </DropdownMenuContent>
+    </DropdownMenu>
+  );
+}

components/ui/alert-dialog.tsx

@@ -0,0 +1,150 @@
+/**
+ * @file components/ui/alert-dialog.tsx
+ * @description 알림 대화상자 (Alert Dialog) 컴포넌트 (Shadcn/ui)
+ * @remarks
+ * - [레이어] Components/UI/Primitive
+ * - [기능] 중요한 작업 확인 컨텍스트 제공 (로그아웃 경고 등)
+ * @see session-manager.tsx - 로그아웃 경고에 사용
+ */
+
+"use client";
+
+import * as React from "react";
+import * as AlertDialogPrimitive from "@radix-ui/react-alert-dialog";
+
+import { cn } from "@/lib/utils";
+import { buttonVariants } from "@/components/ui/button";
+
+const AlertDialog = AlertDialogPrimitive.Root;
+
+const AlertDialogTrigger = AlertDialogPrimitive.Trigger;
+
+const AlertDialogPortal = AlertDialogPrimitive.Portal;
+
+const AlertDialogOverlay = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Overlay>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Overlay>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Overlay
+    className={cn(
+      "fixed inset-0 z-50 bg-black/80 data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0",
+      className,
+    )}
+    {...props}
+    ref={ref}
+  />
+));
+AlertDialogOverlay.displayName = AlertDialogPrimitive.Overlay.displayName;
+
+const AlertDialogContent = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Content>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Content>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPortal>
+    <AlertDialogOverlay />
+    <AlertDialogPrimitive.Content
+      ref={ref}
+      className={cn(
+        "fixed left-[50%] top-[50%] z-50 grid w-full max-w-lg translate-x-[-50%] translate-y-[-50%] gap-4 border bg-background p-6 shadow-lg duration-200 data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 data-[side=bottom]:slide-in-from-top-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 sm:rounded-lg",
+        className,
+      )}
+      {...props}
+    />
+  </AlertDialogPortal>
+));
+AlertDialogContent.displayName = AlertDialogPrimitive.Content.displayName;
+
+const AlertDialogHeader = ({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLDivElement>) => (
+  <div
+    className={cn(
+      "flex flex-col space-y-2 text-center sm:text-left",
+      className,
+    )}
+    {...props}
+  />
+);
+AlertDialogHeader.displayName = "AlertDialogHeader";
+
+const AlertDialogFooter = ({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLDivElement>) => (
+  <div
+    className={cn(
+      "flex flex-col-reverse sm:flex-row sm:justify-end sm:space-x-2",
+      className,
+    )}
+    {...props}
+  />
+);
+AlertDialogFooter.displayName = "AlertDialogFooter";
+
+const AlertDialogTitle = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Title>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Title>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Title
+    ref={ref}
+    className={cn("text-lg font-semibold", className)}
+    {...props}
+  />
+));
+AlertDialogTitle.displayName = AlertDialogPrimitive.Title.displayName;
+
+const AlertDialogDescription = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Description>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Description>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Description
+    ref={ref}
+    className={cn("text-sm text-muted-foreground", className)}
+    {...props}
+  />
+));
+AlertDialogDescription.displayName =
+  AlertDialogPrimitive.Description.displayName;
+
+const AlertDialogAction = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Action>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Action>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Action
+    ref={ref}
+    className={cn(buttonVariants(), className)}
+    {...props}
+  />
+));
+AlertDialogAction.displayName = AlertDialogPrimitive.Action.displayName;
+
+const AlertDialogCancel = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Cancel>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Cancel>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Cancel
+    ref={ref}
+    className={cn(
+      buttonVariants({ variant: "outline" }),
+      "mt-2 sm:mt-0",
+      className,
+    )}
+    {...props}
+  />
+));
+AlertDialogCancel.displayName = AlertDialogPrimitive.Cancel.displayName;
+
+export {
+  AlertDialog,
+  AlertDialogPortal,
+  AlertDialogOverlay,
+  AlertDialogTrigger,
+  AlertDialogContent,
+  AlertDialogHeader,
+  AlertDialogFooter,
+  AlertDialogTitle,
+  AlertDialogDescription,
+  AlertDialogAction,
+  AlertDialogCancel,
+};