refactor(ui): standardize button types and migrate file operations to V3 Action API

src/lib/ae_core/ae_comp__site_config_editor.svelte

@@ -4,6 +4,8 @@
      * Specialized UI for managing site.cfg_json settings.
      * Supports General, AI, Performance, and IDAA-specific configurations.
      */
+    import { Modal } from 'flowbite-svelte';
+    import { untrack } from 'svelte';
     import { 
         Palette, Mail, Brain, Timer, 
         ShieldCheck, CodeXml, Save,