Default markdown editors to preview mode

- Open markdown editors in the rendered preview state instead of raw markdown by default.
- Preserve edit and live views through the editor toolbar.
- Keep the `preview` prop overridable by callers because it is spread after the default.

components/markdown/markdown-widgets.tsx

@@ -9,7 +9,16 @@ import type { RehypeRewriteOptions } from "rehype-rewrite";
 // out of the initial board bundle. Shared here so every place that needs
 // markdown (group notes, to-do details) uses the exact same editor/preview
 // widgets instead of each declaring its own dynamic import.
-export const MDEditor = dynamic(() => import("@uiw/react-md-editor"), { ssr: false });
+const RawMDEditor = dynamic(() => import("@uiw/react-md-editor"), { ssr: false });
+
+// `preview` only seeds the editor's initial mode -- @uiw/react-md-editor
+// owns it as internal state after that, flipped by the edit/live/preview
+// toolbar buttons. Defaulting it to "preview" opens every editor rendered
+// instead of raw markdown, while the toolbar still lets someone drop into
+// "edit" (or the split "live" view) when they want granular control.
+export function MDEditor(props: ComponentProps<typeof RawMDEditor>) {
+  return <RawMDEditor preview="preview" {...props} />;
+}
 
 const RawMarkdownPreview = dynamic(
   () => import("@uiw/react-md-editor").then((mod) => mod.default.Markdown),