Notes editor (#7980)

* Support for thematic breaks

- Use the '-' character

* Improve "read only" mode

* Refactor markdown notes editor

- Revert back to simplemde
- Remove package dependencies for mdxeditor
- Fix up buttons / preview / save sequencing

* Update playwright tests

* Cleanup toolbar buttons

* Enable "side by side" mode

* Update UI text

src/frontend/package.json

@@ -37,7 +37,6 @@
         "@mantine/notifications": "^7.12.2",
         "@mantine/spotlight": "^7.12.2",
         "@mantine/vanilla-extract": "^7.12.2",
-        "@mdxeditor/editor": "^3.11.3",
         "@sentry/react": "^8.27.0",
         "@tabler/icons-react": "^3.14.0",
         "@tanstack/react-query": "^5.53.3",
@@ -49,6 +48,7 @@
         "clsx": "^2.1.1",
         "codemirror": "^6.0.1",
         "dayjs": "^1.11.13",
+        "easymde": "^2.18.0",
         "embla-carousel-react": "^8.2.0",
         "fuse.js": "^7.0.0",
         "html5-qrcode": "^2.3.8",
@@ -61,6 +61,7 @@
         "react-is": "^18.3.1",
         "react-router-dom": "^6.26.1",
         "react-select": "^5.8.0",
+        "react-simplemde-editor": "^5.2.0",
         "react-window": "^1.8.10",
         "recharts": "^2.12.7",
         "styled-components": "^6.1.13",