Implement EasyMDE markdown editor (closes #28)

Adds EasyMDE v2.20.0 as a client-side markdown editor with live preview
for documents, news posts, packet remarks, and comment forms. The editor
toggles on/off with the existing markdown checkbox where applicable, and
is always-on for comment fields. Dark theme overrides are applied via
footer.css to match the Bootstrap Slate theme.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: carlbennett

src/Static/a/easymde.min.css

@@ -3,3 +3,13 @@
  * @copyright MIT
  */
 body > footer { background-color: rgba(0,0,0,0.25); }
+
+.CodeMirror, .editor-toolbar, .editor-preview, .editor-preview-side { background: #272b30; color: #c8c8c8; border-color: #3a3f44; }
+.editor-toolbar a { color: #aaa !important; }
+.editor-toolbar a:hover, .editor-toolbar a.active { background: #3a3f44; color: #fff !important; }
+.editor-toolbar.disabled-for-preview a:not(.no-disable) { color: #555 !important; }
+.editor-toolbar i.separator { border-left-color: #555; border-right-color: #333; }
+.CodeMirror-cursor { border-left-color: #c8c8c8; }
+.CodeMirror-selected { background: #3a3f44; }
+.editor-statusbar { color: #777; }
+.EasyMDEContainer .CodeMirror { border-color: #3a3f44; }

src/Static/a/easymde.min.js

@@ -27,6 +27,7 @@ if ($c)
   $c_user_url    = $c_user->getURI();
   $c_user_avatar = $c_user->getAvatarURI(22);
 }
+$_footer_script = '<script type="text/javascript">(function(){var e=document.getElementById(\'comment-content\');if(e)new EasyMDE({element:e,spellChecker:false,renderingConfig:{singleLineBreaks:false,codeSyntaxHighlighting:true}});}());</script>';
 require('./Includes/header.inc.phtml'); ?>
 <div class="container">
 <? if (is_null($this->getContext()->error) && !is_null($c)) { ?>
@@ -39,7 +40,7 @@ require('./Includes/header.inc.phtml'); ?>
         <a href="<?=$c_user_url?>"><img class="avatar" src="<?=$c_user_avatar?>"/> <?=$c_user_name?></a><br/>
         <time datetime="<?=$c_created_dt->format('c')?>"><?=$c_created_dt->format('D M j, Y g:ia T')?></time>
       </td><td>
-        <textarea class="form-control bg-dark text-light" name="content" cols="80" rows="5" tabindex="1" autofocus="autofocus"><?=$c_content?></textarea>
+        <textarea id="comment-content" class="form-control bg-dark text-light" name="content" cols="80" rows="5" tabindex="1" autofocus="autofocus"><?=$c_content?></textarea>
       </td></tr>
     </tbody></table>
     <a class="btn btn-primary" href="javascript:history.go(-1);">Back</a>

src/Static/a/footer.css

@@ -3,6 +3,7 @@ namespace BNETDocs\Templates\Comment;
 use \BNETDocs\Libraries\Core\UrlFormatter;
 use \BNETDocs\Libraries\User\Authentication;
 use \BNETDocs\Libraries\User\User;
+$_footer_script = ($_footer_script ?? '') . '<script type="text/javascript">(function(){var e=document.getElementById(\'comment-content\');if(e)new EasyMDE({element:e,spellChecker:false,renderingConfig:{singleLineBreaks:false,codeSyntaxHighlighting:true}});}());</script>';
 $active_user = $this->getContext()->active_user ?? Authentication::$user;
 $active_user_id = ($active_user ? $active_user->getId() : null);
 $c_edit_visible_admin = ($active_user && $active_user->getOption(User::OPTION_ACL_COMMENT_MODIFY));

src/Templates/Comment/Edit.phtml

@@ -1,5 +1,6 @@
 <?php /* vim: set colorcolumn= expandtab shiftwidth=2 softtabstop=2 tabstop=4 smarttab: */
-namespace BNETDocs\Templates\Document; ?>
+namespace BNETDocs\Templates\Document;
+$_footer_script = ($_footer_script ?? '') . '<script type="text/javascript">(function(){var t=document.getElementById(\'markdown\'),e=document.getElementById(\'content\'),m=null;if(!t||!e)return;function a(){if(t.checked){if(!m)m=new EasyMDE({element:e,spellChecker:false,renderingConfig:{singleLineBreaks:false,codeSyntaxHighlighting:true}});}else{if(m){m.toTextArea();m=null;}}}a();t.addEventListener(\'change\',a);}());</script>'; ?>
   <form method="POST"<?=(!isset($document_id) || empty($document_id) ? '' : ' action="?id=' . filter_var($document_id, FILTER_SANITIZE_FULL_SPECIAL_CHARS) . '"')?>>
     <div class="form-group">
       <label class="form-label font-weight-bold" for="title">Title:</label><br/>

src/Templates/Comment/Section.inc.phtml

@@ -29,5 +29,6 @@ and/or other countries.
 <script src="<?=UrlFormatter::assetify('highlight/highlight.min.js')?>" type="text/javascript" crossorigin="anonymous" charset="utf8"></script>
 <script defer type="text/javascript">$(document).ready(function(){hljs.highlightAll()});</script>
 <script src="<?=UrlFormatter::assetify('moment-2.29.4.min.js')?>" type="text/javascript" crossorigin="anonymous" charset="utf8"></script>
+<script src="<?=UrlFormatter::assetify('easymde.min.js')?>" type="text/javascript" crossorigin="anonymous" charset="utf8"></script>
 <?=(isset($_footer_script) && !empty($_footer_script) ? $_footer_script : '')?>
 </body></html>

src/Templates/Document/Form.inc.phtml

@@ -229,6 +229,7 @@ function _header_nav_html($nav)
     <link rel="stylesheet" href="<?=UrlFormatter::assetify('bootstrap-4.4.1-slate.min.css')?>" integrity="sha384-tfnMnZ6k273p3mDqSKikc9aXSvumltGq76Tbo+VMydpXeD5EDZwbQWo7nbZz+wc9" crossorigin="anonymous"/>
     <link rel="stylesheet" href="<?=UrlFormatter::assetify('datatables.min.css')?>" type="text/css" media="all"/>
     <link rel="stylesheet" href="<?=UrlFormatter::assetify('highlight/styles/vs2015.min.css')?>" type="text/css" media="all"/>
+    <link rel="stylesheet" href="<?=UrlFormatter::assetify('easymde.min.css')?>" type="text/css" media="all"/>
     <link rel="stylesheet" href="<?=UrlFormatter::assetify('footer.css')?>" type="text/css" media="all"/>
     <link rel="icon" href="<?=UrlFormatter::assetify('VSZX0bJ.png')?>" type="image/png" sizes="156x174"/>
     <script type="text/javascript" src="<?=UrlFormatter::assetify('BNETDocs.js')?>" async></script>

src/Templates/Includes/footer.inc.phtml

@@ -1,5 +1,6 @@
 <?php /* vim: set colorcolumn= expandtab shiftwidth=2 softtabstop=2 tabstop=4 smarttab: */
-namespace BNETDocs\Templates\News; ?>
+namespace BNETDocs\Templates\News;
+$_footer_script = ($_footer_script ?? '') . '<script type="text/javascript">(function(){var t=document.getElementById(\'markdown\'),e=document.getElementById(\'content\'),m=null;if(!t||!e)return;function a(){if(t.checked){if(!m)m=new EasyMDE({element:e,spellChecker:false,renderingConfig:{singleLineBreaks:false,codeSyntaxHighlighting:true}});}else{if(m){m.toTextArea();m=null;}}}a();t.addEventListener(\'change\',a);}());</script>'; ?>
   <form method="POST" action="?<?=($news_post_id ? 'id=' . filter_var($news_post_id, FILTER_SANITIZE_FULL_SPECIAL_CHARS) : '')?>">
     <div class="form-group">
       <label class="font-weight-bold" for="category">Category:</label><br/>

src/Templates/Includes/header.inc.phtml

@@ -3,7 +3,8 @@ namespace BNETDocs\Templates\Packet;
 use \BNETDocs\Libraries\Comment;
 use \BNETDocs\Libraries\Packet\Application as PacketAppLayer;
 use \BNETDocs\Libraries\Packet\Packet;
-use \BNETDocs\Libraries\Packet\Transport as PacketTransportLayer; ?>
+use \BNETDocs\Libraries\Packet\Transport as PacketTransportLayer;
+$_footer_script = ($_footer_script ?? '') . '<script type="text/javascript">(function(){var t=document.getElementById(\'markdown\'),e=document.getElementById(\'remarks\'),m=null;if(!t||!e)return;function a(){if(t.checked){if(!m)m=new EasyMDE({element:e,spellChecker:false,renderingConfig:{singleLineBreaks:false,codeSyntaxHighlighting:true}});}else{if(m){m.toTextArea();m=null;}}}a();t.addEventListener(\'change\',a);}());</script>'; ?>
 <form method="POST">
   <div class="row">
     <div class="col-lg-3">