ui: place oidc button near login

backend/static/styles.css

@@ -139,6 +139,13 @@ body.dark-mode .theme-toggle .sun-icon {
     margin-bottom: 4px;
 }
 
+.login-actions {
+    display: flex;
+    gap: 12px;
+    align-items: center;
+    justify-content: flex-end;
+}
+
 /* Header - Keep the gradient but more professional */
 header {
     background: var(--bg-header);
@@ -730,6 +737,11 @@ textarea:focus {
     .header-meta {
         align-items: flex-start;
     }
+
+    .login-actions {
+        flex-direction: column;
+        align-items: stretch;
+    }
 }
 
 /* NEW STYLES FOR ENHANCED UI */