Stealth coverage (the fork's core value was leaking on secondary surfaces):
- stealth scripts are registered per CDP session, so new tabs (`tab new`) and
cross-origin iframe sessions created after the initial page had NO patches.
Extract apply_stealth_via_mgr/apply_stealth_to_session and re-apply on
tab_new and on iframe attach. Fixes automation markers (and FullLaunch UA)
leaking in new tabs / cross-origin frames.
Resource hygiene (temp profiles filled the disk):
- ChromeProcess::drop already cleans the temp user-data-dir on normal exit, but
a hard kill (kill -9 / version-mismatch restart / crash) skips Drop and leaks
~50MB per session. Add cleanup_orphaned_chrome_profiles() on daemon startup
that sweeps agent-browser-chrome-* temp dirs NOT referenced by any live
process (so an in-use profile is never deleted).