Use v-dompurify-html in SQText to prevent XSS (#1309)

The SQText dashboard component rendered TinyMCE output with v-html,
bypassing the DOMPurify sanitization used by every other component.
Replace with v-dompurify-html (already registered globally in main.ts).

frontend/src/views/dashboard/components/sq-text/index.vue

@@ -16,7 +16,7 @@
       @keyup.stop
       @mousedown.stop
       @dblclick.stop="setEdit"
-      v-html="configItem.propValue"
+      v-dompurify-html="configItem.propValue"
     ></div>
     <editor
       :id="tinymceId"