feat: persistent Chromium daemon with CLI wrapper

Bun-powered HTTP server on localhost keeps headless Chromium alive
between commands. CLI auto-starts server on first call (~3s), subsequent
commands ~100-200ms. Bearer token auth, 30 min idle shutdown, auto-restart
on Chromium crash.

Architecture: compiled CLI binary → HTTP POST → Bun.serve → Playwright

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,4 @@
+node_modules/
+dist/
+/tmp/
+*.log