✨Feat: 공동 사용자 프로필 구현

src/app/dashboard/[id]/edit/layout.tsx

@@ -1,12 +1,15 @@
 import Header from '@components/common/header/Header'
 
+import Sidebar from '@/app/shared/components/common/sidebar/Sidebar'
+
 export default function AboutLayout({
   children,
 }: {
   children: React.ReactNode
 }) {
   return (
     <div>
+      <Sidebar />
       <Header />
       <div>{children}</div> {/* 여기에 page.tsx 내용이 들어옴 */}
     </div>

src/app/shared/components/common/Avatar.tsx

@@ -0,0 +1,66 @@
+'use client'
+
+import Image from 'next/image'
+
+type AvatarProps = {
+  nickname: string
+  imageUrl?: string
+  size?: number
+}
+
+const customColors = [
+  '#efaa8d',
+  '#FFC85A',
+  '#b9ef8d',
+  '#8eef8d',
+  '#8defd3',
+  '#8dcaef',
+  '#8d9def',
+  '#a58def',
+  '#e292e0',
+]
+
+function getInitial(nickname: string): string {
+  const firstChar = nickname.trim().charAt(0)
+  if (/[a-zA-Z]/.test(firstChar)) return firstChar.toUpperCase()
+  if (/[가-힣]/.test(firstChar)) return firstChar
+  return '?'
+}
+
+function getColor(nickname: string): string {
+  const hash = nickname
+    .split('')
+    .reduce((acc, char) => acc + char.charCodeAt(0), 0)
+  return customColors[hash % customColors.length]
+}
+
+export function Avatar({ nickname, imageUrl, size = 36 }: AvatarProps) {
+  const initial = getInitial(nickname)
+  const bgColor = getColor(nickname)
+
+  return imageUrl ? (
+    <div
+      className="relative overflow-hidden rounded-full"
+      style={{ width: size, height: size }}
+    >
+      <Image
+        src={imageUrl}
+        fill
+        alt={`${nickname} 프로필 이미지`}
+        className="object-cover"
+      />
+    </div>
+  ) : (
+    <div
+      className="flex items-center justify-center rounded-full font-semibold text-white"
+      style={{
+        width: size,
+        height: size,
+        fontSize: size * 0.4,
+        backgroundColor: bgColor,
+      }}
+    >
+      {initial}
+    </div>
+  )
+}

src/app/shared/components/common/CollaboratorItem.tsx

@@ -0,0 +1,27 @@
+'use client'
+
+import { cn } from '@lib/cn'
+
+import { Avatar } from './Avatar'
+
+type CollaboratorItemProps = {
+  nickname: string
+  imageUrl?: string
+  size?: number
+  className?: string
+  onClick?: () => void
+}
+
+export default function CollaboratorItem({
+  nickname,
+  imageUrl,
+  size = 48,
+  className,
+  onClick,
+}: CollaboratorItemProps) {
+  return (
+    <div className={cn('flex items-center gap-3', className)} onClick={onClick}>
+      <Avatar nickname={nickname} imageUrl={imageUrl} size={size} />
+    </div>
+  )
+}

src/app/shared/components/common/Dropdown/Dropdown.tsx

@@ -1,59 +1,132 @@
-'use client'
-
-import { cn } from '@lib/cn' // 클래스 이름 병합 유틸리티
-import { ReactNode, useEffect, useRef, useState } from 'react'
+import { useEffect, useRef, useState } from 'react'
+import { createPortal } from 'react-dom'
 
 type DropdownProps = {
-  trigger: ReactNode
-  children: ReactNode
-  align?: 'left' | 'right' | 'center'
+  trigger: React.ReactNode
+  children: React.ReactNode
   width?: string
+  align?: 'left' | 'center' | 'right'
 }
 
 export default function Dropdown({
   trigger,
   children,
-  align = 'center',
-  width = 'w-40',
+  width = 'w-48',
+  align = 'left',
 }: DropdownProps) {
-  const [isOpen, setIsOpen] = useState(false)
-  const ref = useRef<HTMLDivElement>(null)
+  const [open, setOpen] = useState(false)
+  const triggerRef = useRef<HTMLDivElement>(null)
+  const menuRef = useRef<HTMLDivElement>(null)
+  const [coords, setCoords] = useState<{ top: number; left: number }>({
+    top: 0,
+    left: 0,
+  })
+
+  const toggleOpen = () => setOpen((prev) => !prev)
+
+  const getWidthValue = (width: string) => {
+    switch (width) {
+      case 'w-5':
+        {
+          /* 할 일 카드 모달 너비*/
+        }
+        return '5rem'
+      case 'w-6':
+        return '6rem'
+      default:
+        return undefined
+    }
+  }
 
   useEffect(() => {
-    const handleClickOutside = (e: MouseEvent) => {
-      if (ref.current && !ref.current.contains(e.target as Node)) {
-        setIsOpen(false)
+    function updateCoords() {
+      if (open && triggerRef.current) {
+        const rect = triggerRef.current.getBoundingClientRect()
+
+        let left = rect.left
+        if (align === 'center') left = rect.left + rect.width / 2
+        else if (align === 'right') left = rect.right
+
+        setCoords({
+          top: rect.bottom + window.scrollY,
+          left,
+        })
       }
     }
 
-    document.addEventListener('mousedown', handleClickOutside)
-    return () => document.removeEventListener('mousedown', handleClickOutside)
-  }, [])
+    if (open) {
+      updateCoords()
+      window.addEventListener('resize', updateCoords)
+      window.addEventListener('scroll', updateCoords)
+    }
+
+    return () => {
+      window.removeEventListener('resize', updateCoords)
+      window.removeEventListener('scroll', updateCoords)
+    }
+  }, [open, align])
+
+  useEffect(() => {
+    function handleClickOutside(event: MouseEvent) {
+      if (
+        menuRef.current &&
+        !menuRef.current.contains(event.target as Node) &&
+        triggerRef.current &&
+        !triggerRef.current.contains(event.target as Node)
+      ) {
+        setOpen(false)
+      }
+    }
+
+    if (open) {
+      document.addEventListener('mousedown', handleClickOutside)
+    } else {
+      document.removeEventListener('mousedown', handleClickOutside)
+    }
+
+    return () => {
+      document.removeEventListener('mousedown', handleClickOutside)
+    }
+  }, [open])
+
+  const menu = open
+    ? createPortal(
+        <div
+          ref={menuRef}
+          style={{
+            position: 'absolute',
+            top: coords.top,
+            left: coords.left,
+            transform:
+              align === 'center'
+                ? 'translateX(-50%)'
+                : align === 'right'
+                  ? 'translateX(-100%)'
+                  : undefined,
+            width: getWidthValue(width),
+            minWidth: getWidthValue(width),
+            boxShadow: '0 2px 8px rgba(0,0,0,0.15)',
+            borderRadius: 8,
+            zIndex: 9999,
+          }}
+          className="BG-white"
+        >
+          {children}
+        </div>,
+        document.body,
+      )
+    : null
 
   return (
-    <div ref={ref} className="relative inline-block">
+    <>
       <div
-        onClick={() => setIsOpen((prev) => !prev)}
-        className="cursor-pointer"
+        ref={triggerRef}
+        onClick={toggleOpen}
+        className="inline-block cursor-pointer"
       >
         {trigger}
       </div>
-
-      {isOpen && (
-        <div
-          className={cn(
-            'BG-gray absolute z-50 mt-4 rounded border shadow-md',
-            width,
-            {
-              'left-0': align === 'left',
-              'right-0': align === 'right',
-              'left-1/2 -translate-x-1/2': align === 'center',
-            },
-          )}
-        >
-          {children}
-        </div>
-      )}
-    </div>
+      {menu}
+    </>
   )
 }

src/app/shared/components/common/UserInfo.tsx

@@ -0,0 +1,18 @@
+'use client'
+
+import { Avatar } from './Avatar'
+
+type UserInfoProps = {
+  nickname: string
+  imageUrl?: string
+  size?: number
+}
+
+export function UserInfo({ nickname, imageUrl, size = 36 }: UserInfoProps) {
+  return (
+    <div className="flex items-center gap-4">
+      <Avatar nickname={nickname} imageUrl={imageUrl} size={size} />
+      <span className="text-sm font-semibold">{nickname}</span>
+    </div>
+  )
+}