feat(docs): doc-sections system, crdt package, MCP server, and responsive fixes

Adds a hand-authored .vue doc-sections system (intro + guide pages per package, #docs/sections map, sidebar Guide group, client-side TOC), registers @robonen/crdt, renders demos client-only, base64-encodes the server-metadata virtual, plus the MCP docs endpoint and responsive/overflow fixes across pages and tables.

docs/server/routes/mcp.post.ts

@@ -0,0 +1,39 @@
+/**
+ * MCP endpoint, served by the Nuxt/Nitro server itself — no separate process.
+ *
+ * Speaks the MCP Streamable HTTP transport in stateless mode (one fresh server
+ * per request, plain JSON responses), reusing the shared `createDocsMcpServer`
+ * factory and the build-time documentation metadata injected by the extractor
+ * module as the `#docs/server-metadata` virtual.
+ *
+ * POST /mcp  →  start the dev server (`pnpm docs:dev`) and point your MCP client
+ * at http://localhost:3000/mcp.
+ */
+
+import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
+import metadata from '#docs/server-metadata';
+import pkg from '../../package.json';
+import { createDocsMcpServer } from '../../modules/mcp/create-server';
+
+export default defineEventHandler(async (event) => {
+  // h3 has already buffered the JSON body; hand it to the transport so it does
+  // not try to re-read the consumed request stream.
+  const body = await readBody(event);
+
+  const server = createDocsMcpServer(metadata, pkg.version);
+  const transport = new StreamableHTTPServerTransport({
+    sessionIdGenerator: undefined, // stateless: no session tracking for read-only docs
+    enableJsonResponse: true, // return a single JSON response rather than an SSE stream
+  });
+
+  // Tear both down once the response is flushed.
+  event.node.res.on('close', () => {
+    void transport.close();
+    void server.close();
+  });
+
+  await server.connect(transport);
+  // The transport writes the status, headers and body directly to res and ends
+  // it; h3 sees `res.writableEnded` and does not attempt a second response.
+  await transport.handleRequest(event.node.req, event.node.res, body);
+});