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

packages/plugins/sandboxed-test/package.json

@@ -0,0 +1,46 @@
+{
+	"name": "@emdash-cms/plugin-sandboxed-test",
+	"private": true,
+	"version": "0.0.3",
+	"description": "Test plugin for sandboxed plugin system",
+	"type": "module",
+	"main": "dist/index.mjs",
+	"exports": {
+		".": {
+			"import": "./dist/index.mjs",
+			"types": "./dist/index.d.mts"
+		},
+		"./sandbox": "./dist/sandbox-entry.mjs"
+	},
+	"files": [
+		"dist"
+	],
+	"scripts": {
+		"build": "tsdown src/index.ts src/sandbox-entry.ts --format esm --dts --clean",
+		"dev": "tsdown src/index.ts src/sandbox-entry.ts --format esm --dts --watch",
+		"typecheck": "tsgo --noEmit"
+	},
+	"keywords": [
+		"emdash",
+		"cms",
+		"plugin",
+		"test",
+		"sandbox"
+	],
+	"author": "Matt Kane",
+	"license": "MIT",
+	"dependencies": {
+		"emdash": "workspace:*"
+	},
+	"devDependencies": {
+		"tsdown": "catalog:",
+		"typescript": "catalog:"
+	},
+	"peerDependencies": {},
+	"optionalDependencies": {},
+	"repository": {
+		"type": "git",
+		"url": "git+https://github.com/emdash-cms/emdash.git",
+		"directory": "packages/plugins/sandboxed-test"
+	}
+}