Fix workspace selection and secret modal layout

apps/ui/css/pages.css

@@ -767,7 +767,10 @@
   border-radius: 12px;
   width: 100%;
   max-width: 480px;
+  max-height: calc(100dvh - 48px);
   box-shadow: 0 8px 40px rgba(0,0,0,0.6);
+  display: flex;
+  flex-direction: column;
   overflow: hidden;
 }
 
@@ -801,8 +804,8 @@
 }
 .modal-close:hover { background: var(--bg-overlay); color: var(--text-primary); }
 
-.modal-body { padding: 20px; }
-.modal-footer { padding: 14px 20px; border-top: 1px solid var(--border-subtle); display: flex; justify-content: flex-end; gap: 8px; }
+.modal-body { padding: 20px; overflow: auto; }
+.modal-footer { padding: 14px 20px; border-top: 1px solid var(--border-subtle); display: flex; justify-content: flex-end; gap: 8px; flex-shrink: 0; }
 
 /* ══════════════════════════════════════════════════
    RESPONSIVE