fix: Synology SSO Implicit Grant 방식으로 변경

- response_type: code → token
- redirect_uri: /api/... → /auth/... (프론트엔드 페이지)
- 프론트엔드 callback 페이지 추가 (hash fragment 파싱)
- verify API 추가 (access_token 검증)

nuxt.config.ts

@@ -65,7 +65,7 @@ export default defineNuxtConfig({
     synologyServerUrl: process.env.SYNOLOGY_SERVER_URL || 'https://sso.osolit.net',
     synologyClientId: process.env.SYNOLOGY_CLIENT_ID || 'afa90b7b4a9773af41f2c7b110f92d6e',
     synologyClientSecret: process.env.SYNOLOGY_CLIENT_SECRET || '',
-    synologyRedirectUri: process.env.SYNOLOGY_REDIRECT_URI || 'https://weeklyreport.turbosoft.kr/api/auth/synology/callback',
+    synologyRedirectUri: process.env.SYNOLOGY_REDIRECT_URI || 'https://weeklyreport.turbosoft.kr/auth/synology/callback',
     public: {
       appName: '주간업무보고'
     }