docs: 交付文档、维护指引与端到端回归

补齐 README、开发计划、维护交接与 E2E 用例，执行最终验收。

e2e/services/fake-mcp/server.ts

@@ -0,0 +1,88 @@
+// A real MCP server (streamable HTTP, stateless) for the MCP-connector journeys:
+// the backend connects to it exactly as it would to a customer's server, lists
+// its tools and calls them when the (fake) model asks.
+//
+//   POST /mcp               the MCP endpoint
+//   GET  /__requests        the headers each MCP request arrived with, oldest first
+//   DELETE /__requests      forget them
+//
+// Tools: lookup_order(order_id) → "Order <id>: shipped on 2 May via DHL".
+//
+// Run: node services/fake-mcp/server.ts --port 14030
+
+import { createServer, type IncomingMessage, type ServerResponse } from 'node:http'
+import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
+import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js'
+import { z } from 'zod'
+
+interface SeenRequest {
+  at: string
+  method: string
+  authorization: string | null
+  rpcMethod: string | null
+}
+
+const seen: SeenRequest[] = []
+
+function mcpServer(): McpServer {
+  const server = new McpServer({ name: 'e2e-orders', version: '1.0.0' })
+  server.registerTool('lookup_order', {
+    description: 'Look up an order by its id and return its shipping status.',
+    inputSchema: { order_id: z.string().describe('The order id, e.g. A123') },
+  }, async ({ order_id }) => ({
+    content: [{ type: 'text', text: `Order ${order_id}: shipped on 2 May via DHL` }],
+  }))
+  return server
+}
+
+async function readJson(req: IncomingMessage): Promise<unknown> {
+  const chunks: Buffer[] = []
+  for await (const chunk of req) chunks.push(chunk as Buffer)
+  const raw = Buffer.concat(chunks).toString('utf8')
+  return raw ? JSON.parse(raw) : undefined
+}
+
+function send(res: ServerResponse, status: number, body: unknown) {
+  res.writeHead(status, { 'content-type': 'application/json' })
+  res.end(JSON.stringify(body))
+}
+
+async function route(req: IncomingMessage, res: ServerResponse) {
+  const path = new URL(req.url ?? '/', 'http://fake-mcp').pathname
+  if (path === '/health') return send(res, 200, { status: 'ok' })
+  if (path === '/__requests' && req.method === 'GET') return send(res, 200, seen)
+  if (path === '/__requests' && req.method === 'DELETE') {
+    seen.length = 0
+    return send(res, 200, { ok: true })
+  }
+  if (path !== '/mcp') return send(res, 404, { error: `no route for ${path}` })
+  if (req.method !== 'POST') return send(res, 405, { jsonrpc: '2.0', error: { code: -32000, message: 'Method not allowed.' }, id: null })
+
+  const body = await readJson(req)
+  seen.push({
+    at: new Date().toISOString(),
+    method: req.method,
+    authorization: req.headers.authorization ?? null,
+    rpcMethod: (body as { method?: string } | undefined)?.method ?? null,
+  })
+  // Stateless: a fresh server and transport per request, as the SDK recommends.
+  const server = mcpServer()
+  const transport = new StreamableHTTPServerTransport({ sessionIdGenerator: undefined })
+  res.on('close', () => {
+    void transport.close()
+    void server.close()
+  })
+  await server.connect(transport)
+  await transport.handleRequest(req, res, body)
+}
+
+const portArg = process.argv.indexOf('--port')
+const port = Number(portArg > -1 ? process.argv[portArg + 1] : 14030)
+
+createServer((req, res) => {
+  route(req, res).catch((err: unknown) => {
+    const message = err instanceof Error ? err.message : String(err)
+    console.error(`[fake-mcp] ${req.method} ${req.url} -> 500: ${message}`)
+    if (!res.headersSent) send(res, 500, { error: message })
+  })
+}).listen(port, '127.0.0.1', () => console.log(`[fake-mcp] listening on http://127.0.0.1:${port}/mcp`))