fix(test): make a bare vitest invocation use the isolated CI config

`npx vitest run` with no --config found no config file, so test/setup.ts never ran and HOME
was not redirected: the suite wrote fixtures (clis.json with a test entry, users.json,
webhook.json, intents.json, .env, settings.json values) into the developer's real ~/.codeman,
and a running Codeman then loaded them on its next restart.

A root vitest.config.ts re-exports config/vitest.ci.config.ts, so the default invocation is the
isolated one; npm test and the browser/mobile/perf scripts keep passing their own --config. The
shared temp-HOME teardown also retries on ENOTEMPTY, which failed whole files intermittently
after every test had passed.

test/setup.ts

@@ -121,7 +121,9 @@ afterAll(async () => {
   if (originalPlaywrightBrowsersPath === undefined) delete process.env.PLAYWRIGHT_BROWSERS_PATH;
   else process.env.PLAYWRIGHT_BROWSERS_PATH = originalPlaywrightBrowsersPath;
 
-  rmSync(testHome, { recursive: true, force: true });
+  // maxRetries: a straggling writer (a server persisting on shutdown) can recreate a file between
+  // rmSync's readdir and rmdir, which fails the whole file with ENOTEMPTY after every test passed.
+  rmSync(testHome, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
 });
 
 // afterAll never fires for a fully-skipped test file (no tests execute), which

test/test-env-isolation.test.ts

@@ -78,3 +78,16 @@ describe('test environment isolation', () => {
     expect(deleted).toEqual(STRIPPED_ENV_VARS.map(([name]) => name).sort());
   });
 });
+
+describe('a bare vitest invocation is still isolated', () => {
+  // Without a root config, `npx vitest run` loads no setup file, so HOME is never redirected and
+  // the suite writes fixtures into the developer's real ~/.codeman. Pin that the root config
+  // exists and carries the setup file, rather than trusting everyone to pass --config.
+  it('has a root vitest.config.ts that loads test/setup.ts', () => {
+    const root = fileURLToPath(new URL('..', import.meta.url));
+    const src = readFileSync(`${root}vitest.config.ts`, 'utf8');
+    expect(src).toContain('./config/vitest.ci.config');
+    const ci = readFileSync(`${root}config/vitest.ci.config.ts`, 'utf8');
+    expect(ci).toContain("setupFiles: ['./test/setup.ts']");
+  });
+});