fix: import CSS globally for custom field z-index fix

[FIX] Import EditorJS styles.css and ai-assistant.css in index.js to ensure CSS is loaded when used as Custom Field
[FIX] Also import styles.css in EditorJS component directly
[FIX] This ensures z-index: 9999 for popovers is applied in Content Manager custom field usage

Author: Schero94

admin/src/components/EditorJS/index.jsx

@@ -43,6 +43,7 @@ import VersionHistoryPanel from '../VersionHistoryPanel';
 import AIInlineToolbar from '../AIInlineToolbar';
 import { AIToast, toastManager } from '../AIToast';
 import CreditsModal from '../CreditsModal';
+import './styles.css';
 import '../../styles/ai-assistant.css';
 
 /* ============================================

admin/src/index.js

@@ -7,6 +7,10 @@ import { PLUGIN_ID } from './pluginId';
 import { Initializer } from './components/Initializer';
 import { PluginIcon } from './components/PluginIcon';
 
+// Import CSS globally so it's available in Custom Field
+import './components/EditorJS/styles.css';
+import './styles/ai-assistant.css';
+
 // Prefix translation keys with pluginId (required for Strapi)
 const prefixPluginTranslations = (data, pluginId) => {
   const prefixed = {};