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/is.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 n=jQuery.fn.select2.amd;n.define("select2/i18n/is",[],function(){return{inputTooLong:function(n){var t=n.input.length-n.maximum,e="Vinsamlegast styttið texta um "+t+" staf";return t<=1?e:e+"i"},inputTooShort:function(n){var t=n.minimum-n.input.length,e="Vinsamlegast skrifið "+t+" staf";return t>1&&(e+="i"),e+=" í viðbót"},loadingMore:function(){return"Sæki fleiri niðurstöður…"},maximumSelected:function(n){return"Þú getur aðeins valið "+n.maximum+" atriði"},noResults:function(){return"Ekkert fannst"},searching:function(){return"Leita…"},removeAllItems:function(){return"Fjarlægðu öll atriði"}}}),n.define,n.require}();