fix: quiet update banner and skip duplicate plugin CLI

src/plugins/cli.test.ts

@@ -0,0 +1,45 @@
+import { Command } from "commander";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const mocks = vi.hoisted(() => ({
+  memoryRegister: vi.fn(),
+  otherRegister: vi.fn(),
+}));
+
+vi.mock("./loader.js", () => ({
+  loadClawdbotPlugins: () => ({
+    cliRegistrars: [
+      {
+        pluginId: "memory-core",
+        register: mocks.memoryRegister,
+        commands: ["memory"],
+        source: "bundled",
+      },
+      {
+        pluginId: "other",
+        register: mocks.otherRegister,
+        commands: ["other"],
+        source: "bundled",
+      },
+    ],
+  }),
+}));
+
+import { registerPluginCliCommands } from "./cli.js";
+
+describe("registerPluginCliCommands", () => {
+  beforeEach(() => {
+    mocks.memoryRegister.mockClear();
+    mocks.otherRegister.mockClear();
+  });
+
+  it("skips plugin CLI registrars when commands already exist", () => {
+    const program = new Command();
+    program.command("memory");
+
+    registerPluginCliCommands(program, {} as any);
+
+    expect(mocks.memoryRegister).not.toHaveBeenCalled();
+    expect(mocks.otherRegister).toHaveBeenCalledTimes(1);
+  });
+});