fix: missing closing paren in t() call causing SyntaxError in ui.js

The template literal ${t('modal.in_folder', {path: parentPath || '/'}\nwas missing the closing )} — the / after || was interpreted\nas the start of a regex literal, causing:\n  Uncaught SyntaxError: Invalid regular expression: missing /

Fixed both occurrences (directory + file create modals).

frontend/js/ui.js

@@ -660,7 +660,7 @@ const FileOperations = {
         <div class="modal-form-group">
           <label class="modal-label">Nom du dossier</label>
           <input type="text" class="modal-input" id="dir-name-input" placeholder="nouveau-dossier" />
-          <div class="modal-hint">${t('modal.in_folder', {path: parentPath || '/'}</div>
+          <div class="modal-hint">${t('modal.in_folder', {path: parentPath || '/'})}</div>
           <div class="modal-error" id="dir-error" style="display:none;"></div>
         </div>
       </div>
@@ -751,7 +751,7 @@ const FileOperations = {
         <div class="modal-form-group">
           <label class="modal-label">${t('modal.file_name')}</label>
           <input type="text" class="modal-input" id="file-name-input" placeholder="note.md" />
-          <div class="modal-hint">${t('modal.in_folder', {path: parentPath || '/'}</div>
+          <div class="modal-hint">${t('modal.in_folder', {path: parentPath || '/'})}</div>
           <div class="modal-error" id="file-error" style="display:none;"></div>
         </div>
         <div class="modal-form-group">