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

docs/src/worker.ts

@@ -0,0 +1,86 @@
+import { handle } from "@astrojs/cloudflare/handler";
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { createMcpHandler } from "agents/mcp";
+import { z } from "zod";
+
+/**
+ * Build a fresh McpServer per request. createMcpHandler is stateless, and the
+ * underlying transport asserts that the server is not already connected, so we
+ * cannot reuse a single server instance across requests.
+ */
+function buildMcpServer(env: Env): McpServer {
+	const server = new McpServer({
+		name: "emdash-docs",
+		version: "1.0.0",
+	});
+
+	server.registerTool(
+		"search_docs",
+		{
+			title: "Search EmDash documentation",
+			description:
+				"Search the EmDash CMS documentation. Returns relevant chunks with source URLs and similarity scores.",
+			inputSchema: {
+				query: z
+					.string()
+					.min(1)
+					.max(1000)
+					.describe("Natural-language query against the EmDash docs."),
+				max_results: z
+					.number()
+					.int()
+					.min(1)
+					.max(20)
+					.optional()
+					.describe("Maximum number of chunks to return. Defaults to 8."),
+			},
+		},
+		async ({ query, max_results }) => {
+			const limit = max_results ?? 8;
+
+			const results = await env.AI_SEARCH.search({
+				messages: [{ role: "user", content: query }],
+				ai_search_options: {
+					retrieval: { max_num_results: limit },
+				},
+			});
+
+			if (!results.chunks.length) {
+				return {
+					content: [
+						{
+							type: "text",
+							text: "No matching docs found.",
+						},
+					],
+				};
+			}
+
+			return {
+				content: results.chunks.map((chunk) => {
+					const source = chunk.item.key;
+					const score = typeof chunk.score === "number" ? chunk.score.toFixed(3) : "n/a";
+					return {
+						type: "text" as const,
+						text: `<result source="${source}" score="${score}">\n${chunk.text}\n</result>`,
+					};
+				}),
+			};
+		},
+	);
+
+	return server;
+}
+
+export default {
+	async fetch(request: Request, env: Env, ctx: ExecutionContext): Promise<Response> {
+		const url = new URL(request.url);
+
+		if (url.pathname === "/mcp") {
+			const handler = createMcpHandler(buildMcpServer(env), { route: "/mcp" });
+			return handler(request, env, ctx);
+		}
+
+		return handle(request, env, ctx);
+	},
+} satisfies ExportedHandler<Env>;