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

skills/wordpress-theme-to-emdash/scaffold/src/env.d.ts

@@ -0,0 +1,2 @@
+/// <reference path="../.astro/types.d.ts" />
+/// <reference types="astro/client" />