refactor: Inline-Styles durch CSS-Klassen ersetzt

- 40+ Utility-Klassen in form.css (clickable, text-danger, flex-row, loading-state, etc.)
- share-menu position/z-index in chat.css statt inline
- index.html: 0 Inline-Styles (hidden-Attribut, CSS-Klassen)
- 12 JS-Dateien bereinigt: style.cssText/style.* durch classList ersetzt
- Bugfix: var(--danger) → var(--dangerous) (nicht existierende Variable)
- display:none Toggles → hidden-Attribut wo passend
- Hardcoded font-sizes in chat.css → var(--font-size)

15 Dateien, nur Frontend (CSS/JS/HTML), kein Backend

wwwroot/js/bubbles.js

@@ -72,7 +72,7 @@ function _renderUserTextContent(container, raw, inlineImages) {
     const filePath = ref.replace(/:\d+(-\d+)?$/, '');
     const fileName = filePath.includes('/') ? filePath.substring(filePath.lastIndexOf('/') + 1) : filePath;
     const lineInfo = ref.replace(filePath, '').trim();
-    return '<span class="file-ref-chip" data-filepath="' + esc(filePath) + '" title="' + esc(ref) + '" style="cursor:pointer">'
+    return '<span class="file-ref-chip clickable" data-filepath="' + esc(filePath) + '" title="' + esc(ref) + '">'
       + '<i class="fa fa-file-text-o"></i> ' + esc(fileName + lineInfo) + '</span>';
   });
 
@@ -141,7 +141,7 @@ function createAttachmentIndicator(messageId, count, namesJson) {
   const ind = document.createElement('div');
   ind.className = 'attachment-indicator';
   ind.innerHTML = `<i class="fa fa-paperclip"></i> ${count} Datei${count > 1 ? 'en' : ''}` + (nameList ? `: ${esc(nameList)}` : '');
-  ind.style.cursor = 'pointer';
+  ind.classList.add('clickable');
   ind.title = 'Klicken zum Anzeigen';
   ind.addEventListener('click', () => loadAndShowAttachments(messageId, ind));
   return ind;