ci: enforce flutter/biome format checks and fix front lint violations

userfront/lib/core/services/auth_proxy_service.dart

@@ -299,10 +299,7 @@ class AuthProxyService {
       } else {
         final errorBody = jsonDecode(response.body);
         throw Exception(
-          errorBody['error'] ??
-              tr(
-                'err.userfront.auth_proxy.consent_fetch',
-              ),
+          errorBody['error'] ?? tr('err.userfront.auth_proxy.consent_fetch'),
         );
       }
     } finally {
@@ -333,10 +330,7 @@ class AuthProxyService {
       } else {
         final errorBody = jsonDecode(response.body);
         throw Exception(
-          errorBody['error'] ??
-              tr(
-                'err.userfront.auth_proxy.consent_accept',
-              ),
+          errorBody['error'] ?? tr('err.userfront.auth_proxy.consent_accept'),
         );
       }
     } finally {
@@ -363,10 +357,7 @@ class AuthProxyService {
       } else {
         final errorBody = jsonDecode(response.body);
         throw Exception(
-          errorBody['error'] ??
-              tr(
-                'err.userfront.auth_proxy.consent_reject',
-              ),
+          errorBody['error'] ?? tr('err.userfront.auth_proxy.consent_reject'),
         );
       }
     } finally {