fix: resolve OIDC session state issue and synchronize portal sessions

Details:
- Backend: Extract Kratos session cookies and propagate via SetCookies in AuthInfo.
- Backend: Include sessionJwt and token during OIDC flows in PasswordLogin.
- UserFront: Add _silentSessionRecovery in main.dart to recover session via cookies if localStorage token is missing.
- UserFront: Update AuthProxyService, AuthTokenStore, AuthNotifier to support silent recovery and immediate local state update before redirect.
- AdminFront/DevFront: Fix OIDC authority to point directly to Gateway proxy and add recovery/error UI components.

backend/internal/domain/idp_models.go

@@ -53,6 +53,7 @@ type AuthInfo struct {
 	RefreshToken *Token
 	// Subject는 IDP 세션이 대표하는 주체(예: Kratos identity.id)를 나타냅니다.
 	Subject string
+	SetCookies   []*http.Cookie
 }
 
 // LinkLoginInit는 링크 로그인 초기화 결과입니다.