fix(auth): set SameSite=None for session cookies to fix cross-origin session loss in Tauri apps

internal/auth/cookie.go

@@ -17,7 +17,7 @@ func SetSessionCookie(w http.ResponseWriter, cookieName, token string, duration
 		Path:     "/",
 		HttpOnly: true,
 		Secure:   secure,
-		SameSite: http.SameSiteLaxMode,
+		SameSite: http.SameSiteNoneMode,
 		MaxAge:   int(duration.Seconds()),
 	})
 }