feat(editor): update TipTap dependencies and enhance table functionality

- Added @tiptap/core version 3.13.0 to package.json and updated related dependencies in pnpm-lock.yaml.
- Refactored RichEditor to utilize new table extension with responsive wrapper and improved styling.
- Adjusted editor mode initialization in MDEditor to default to 'rich' for enhanced user experience.
- Removed redundant styles from index.scss to streamline the editor's appearance.

Author: robin

ui/package.json

@@ -21,6 +21,7 @@
     "@codemirror/language-data": "^6.5.0",
     "@codemirror/state": "^6.5.0",
     "@codemirror/view": "^6.26.1",
+    "@tiptap/core": "^3.13.0",
     "@tiptap/extension-image": "^3.11.1",
     "@tiptap/extension-placeholder": "^3.11.1",
     "@tiptap/extension-table": "^3.11.1",