feat(auth): iOS 애플 로그인 버튼 — Sign in with Apple(App Store 4.8 대응)

- @capacitor-community/apple-sign-in + LoginModal Apple 버튼(iOS 전용, HIG 검은 버튼)
- appleAuth 네이티브 래퍼 + authApi/auth store appleLogin
- SPM capacitor-swift-pm 8.x 로 패치(patch-package) — @capawesome 구글 플러그인과 iOS 공존
- App.entitlements(applesignin) 준비 — Xcode 'Sign in with Apple' Capability 추가 시 사용

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/stores/auth.js

@@ -77,6 +77,14 @@ export const useAuthStore = defineStore('auth', () => {
     await persist()
     return res
   }
+  async function appleLogin(identityToken, name, rememberMe = true) {
+    const res = await authApi.appleLogin({ identityToken, name, rememberMe })
+    token.value = res.token
+    user.value = res.member
+    exitDemo()
+    await persist()
+    return res
+  }
 
   async function signup(payload) {
     return authApi.signup(payload)
@@ -123,7 +131,7 @@ export const useAuthStore = defineStore('auth', () => {
     await persist()
   }
 
-  return { token, user, ready, isAuthenticated, isAdmin, isPremium, restore, login, googleLogin, signup, fetchMe, applyUser, refreshProfile, logout, clear }
+  return { token, user, ready, isAuthenticated, isAdmin, isPremium, restore, login, googleLogin, appleLogin, signup, fetchMe, applyUser, refreshProfile, logout, clear }
 })
 
 function safeParse(value) {