initial: @a2a/mcp gateway for a2acloud agents

Local MCP server that exposes any number of deployed A2A agents to
Claude Code, Cursor, Windsurf, and other MCP clients. Reuses the
~/.a2a/credentials.json token written by the Python a2a CLI. Adding
or removing agents is a single ~/.a2a/mcp.json edit.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/config.test.ts

@@ -0,0 +1,46 @@
+import { test, beforeEach, afterEach } from "node:test";
+import assert from "node:assert/strict";
+import os from "node:os";
+import path from "node:path";
+import { promises as fs } from "node:fs";
+
+import { addAgent, loadConfig, removeAgent } from "../src/config.js";
+
+let originalHome: string | undefined;
+let tmpHome: string;
+
+beforeEach(async () => {
+  originalHome = process.env.HOME;
+  tmpHome = await fs.mkdtemp(path.join(os.tmpdir(), "a2a-mcp-"));
+  process.env.HOME = tmpHome;
+});
+
+afterEach(async () => {
+  if (originalHome !== undefined) process.env.HOME = originalHome;
+  else delete process.env.HOME;
+  await fs.rm(tmpHome, { recursive: true, force: true });
+});
+
+test("loadConfig returns empty when file is missing", async () => {
+  const cfg = await loadConfig();
+  assert.deepEqual(cfg, { version: 1, agents: [] });
+});
+
+test("addAgent persists and replaces by name", async () => {
+  await addAgent({ name: "a", url: "https://x", addedAt: "t1" });
+  await addAgent({ name: "b", url: "https://y", addedAt: "t1" });
+  await addAgent({ name: "a", url: "https://z", addedAt: "t2" });
+  const cfg = await loadConfig();
+  assert.deepEqual(
+    cfg.agents.map((a) => `${a.name}:${a.url}`),
+    ["a:https://z", "b:https://y"],
+  );
+});
+
+test("removeAgent reports hit/miss", async () => {
+  await addAgent({ name: "a", url: "https://x", addedAt: "t" });
+  assert.equal(await removeAgent("missing"), false);
+  assert.equal(await removeAgent("a"), true);
+  const cfg = await loadConfig();
+  assert.equal(cfg.agents.length, 0);
+});