realbrowser 0.2.1

This release hardens 0.2.0 for parallel Codex sessions and lower-approval
real-browser workflows.

Added:

• Owner-scoped labels, default context, and element refs via --owner /
  REALBROWSER_OWNER.
• Target leases for mutating commands so parallel Codex sessions do not
  accidentally control each other's tabs.
• Owner-separated anonymous daemons while keeping real signed-in browser
  endpoints shared per physical browser endpoint.
• Local JSON state locking for labels, target metadata, leases, and owner default
  contexts.
• Daemon runtime schema checks so old same-version daemons are restarted when the
  state/lease model changes.

Changed:

• tab ensure skips another owner's URL match and creates a fresh tab instead
  of reusing a leased target.
• HTTP and direct WebSocket forms of the same CDP endpoint are treated as the
  same browser endpoint for daemon reuse.
• Chrome browser-wide permission grant/reset now requires --force, even after
  the target lease check passes.
• Full, responsive/device, and annotated screenshots/checkpoints are
  lease-guarded because they temporarily scroll, emulate, or draw page overlays.
• Expanded docs for multi-Codex operation, Chrome approval prompt limits, and
  release validation.

Fixed:

• Owner-scoped refs prevent one session's b1/e1 reads from overwriting
  another session's pending action refs.
• Cross-owner lease detection now considers duplicate/stale lease records and
  keeps the newest relevant lease.
• Broadened mutating raw CDP detection for devtools raw.
• Preserved the realbrowser name consistently across code and docs.
• Set the script version to 0.2.1.