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/x402/src/middleware.ts

@@ -0,0 +1,25 @@
+/**
+ * x402 Astro Middleware
+ *
+ * Injected by the x402 integration. Creates the enforcer and
+ * places it on Astro.locals.x402 for use in page frontmatter.
+ *
+ * The config is passed via the virtual module resolved by the integration.
+ */
+
+import { defineMiddleware } from "astro:middleware";
+// The integration injects config via a virtual module.
+// @ts-ignore -- virtual module, resolved at build time
+import x402Config from "virtual:x402/config";
+
+import { createEnforcer } from "./enforcer.js";
+import type { X402Config } from "./types.js";
+
+// eslint-disable-next-line typescript-eslint/no-unsafe-type-assertion -- virtual module import has no type info
+const config: X402Config = x402Config as X402Config;
+const enforcer = createEnforcer(config);
+
+export const onRequest = defineMiddleware(async (context, next) => {
+	context.locals.x402 = enforcer;
+	return next();
+});