chore: 将后端移动到 api/ 目录，准备合并为单仓库

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

api/static/admin/js/vendor/select2/i18n/da.js

@@ -0,0 +1,3 @@
+/*! Select2 4.0.13 | https://github.com/select2/select2/blob/master/LICENSE.md */
+
+!function(){if(jQuery&&jQuery.fn&&jQuery.fn.select2&&jQuery.fn.select2.amd)var e=jQuery.fn.select2.amd;e.define("select2/i18n/da",[],function(){return{errorLoading:function(){return"Resultaterne kunne ikke indlæses."},inputTooLong:function(e){return"Angiv venligst "+(e.input.length-e.maximum)+" tegn mindre"},inputTooShort:function(e){return"Angiv venligst "+(e.minimum-e.input.length)+" tegn mere"},loadingMore:function(){return"Indlæser flere resultater…"},maximumSelected:function(e){var n="Du kan kun vælge "+e.maximum+" emne";return 1!=e.maximum&&(n+="r"),n},noResults:function(){return"Ingen resultater fundet"},searching:function(){return"Søger…"},removeAllItems:function(){return"Fjern alle elementer"}}}),e.define,e.require}();