fix(admin): replicate reference advanced-filter settings page 1:1

- Rewrite post_list/filter schema (PHP + JS) with the reference theme's
  field set, order, defaults and dependencies; topics fields excluded
  (no topics taxonomy), AKSRT private filter_* toggles dropped
- Support dynamic checkbox options in AksField (options as formData key)
  so cat_custom_filter.custom_filters lists the custom_filter dimensions
- Map PostDisplay filter settings to the new keys without legacy fallback;
  cat_custom_filter now carries lists/dropdown fieldsets and array filters
- Wire the archive chain to reference semantics: cat_custom_filter
  overrides per-category filter projects, custom_filter_show gates the
  default display, dimension chip groups render on category/tag archives
- Filter archive queries (main query + AJAX endpoint) by _aksrt_cf_{key}
  meta with exact-quoted LIKE matching
- Add advanced-filter settings reference contract test

src/Settings/Settings.php

@@ -666,9 +666,9 @@ class Settings {
 
 
     /**
-     * Post-list filter toolbar settings.
+     * Post-list advanced filter settings (reference parity).
      *
-     * @return array{enabled:bool,categories:bool,tags:bool,sort:bool}
+     * @return array{custom_filter_show:array,custom_filter:array,cat_custom_filter:array}
      */
     public static function get_post_filter_settings(): array {
         return PostDisplay::get_post_filter_settings();
@@ -677,14 +677,14 @@ class Settings {
 
 
     /**
-     * Get custom filter definitions for a specific category.
-     * Finds the matching cat_custom_filter binding, falls back to global custom_filter.
+     * Archive custom filter config (cat_custom_filter override + custom_filter_show gate).
      *
-     * @param int $cat_id Category term ID.
-     * @return array{dimensions: array, show_cat: bool, show_tag: bool, show_orderby: bool}
+     * @param int    $term_id Category term ID.
+     * @param string $page    cat|tag.
+     * @return array{custom_enabled:bool,custom_filters:mixed,overrides:array<string,mixed>}
      */
-    public static function get_filter_config_for_category(int $cat_id): array {
-        return PostDisplay::get_filter_config_for_category($cat_id);
+    public static function get_archive_custom_filter_config(int $term_id, string $page): array {
+        return PostDisplay::get_archive_custom_filter_config($term_id, $page);
     }