Emdash source with visual editor image upload fix

Fixes:
1. media.ts: wrap placeholder generation in try-catch
2. toolbar.ts: check r.ok, display error message in popover

demos/simple/src/live.config.ts

@@ -0,0 +1,13 @@
+/**
+ * EmDash Live Content Collections
+ *
+ * Defines the _emdash collection that handles all content types from the database.
+ * Query specific types using getEmDashCollection() and getEmDashEntry().
+ */
+
+import { defineLiveCollection } from "astro:content";
+import { emdashLoader } from "emdash/runtime";
+
+export const collections = {
+	_emdash: defineLiveCollection({ loader: emdashLoader() }),
+};