feat(cli): add global entrypoint with doctor/update/uninstall commands

tests/cli/beadboard-cli.test.ts

@@ -0,0 +1,22 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { runCli } from '../../src/cli/beadboard-cli';
+
+test('doctor returns structured install diagnostics', async () => {
+  const out = await runCli(['doctor', '--json']);
+  assert.equal(out.ok, true);
+  assert.ok(out.installMode);
+});
+
+test('self-update returns explicit placeholder result', async () => {
+  const out = await runCli(['self-update', '--json']);
+  assert.equal(out.ok, true);
+  assert.equal(out.command, 'self-update');
+  assert.equal(out.updated, false);
+});
+
+test('uninstall requires --yes', async () => {
+  const out = await runCli(['uninstall', '--json']);
+  assert.equal(out.ok, false);
+  assert.match(out.error, /--yes/);
+});