🎨 优化扩展模块，完成ai接入和对话功能

data/st-core-scripts/lib/select2-search-placeholder.js

@@ -0,0 +1,25 @@
+(function($) {
+
+    var Defaults = $.fn.select2.amd.require('select2/defaults');
+
+    $.extend(Defaults.defaults, {
+        searchInputPlaceholder: '',
+        searchInputCssClass: '',
+    });
+
+    var SearchDropdown = $.fn.select2.amd.require('select2/dropdown/search');
+
+    var _renderSearchDropdown = SearchDropdown.prototype.render;
+
+    SearchDropdown.prototype.render = function(decorated) {
+
+        // invoke parent method
+        var $rendered = _renderSearchDropdown.apply(this, Array.prototype.slice.apply(arguments));
+
+        this.$search.attr('placeholder', this.options.get('searchInputPlaceholder'));
+        this.$search.addClass(this.options.get('searchInputCssClass'));
+
+        return $rendered;
+    };
+
+})(window.jQuery);