Release v0.1.20

[marcelormendes]

Summary

• settle Chat Working and pinned TODO state when an OMP final answer arrives
• pin fork engine v0.8.4, which distinguishes terminal OMP lifecycle events and publishes live metadata
• add the neobrutalist active/queued TODO treatment and readable long-running durations
• render model, thinking, context, cost, cwd, and Git metadata below the Chat composer
• refresh stale restart-needed status after event-stream handoff
• bump Drover to v0.1.20

Validation

• npm run verify
• 64 test files and 558 tests passed
• isolated browser smoke: final answer removed stale Working and active TODO despite stale pane Working metadata
• Herdr engine v0.8.4 release workflow succeeded with four verified platform binaries and SHA256SUMS

Checklist

• The change is focused and does not include unrelated work.
• Tests cover new behavior.
• npm run verify passes locally.
• No credentials, tokens, private data, or generated build artifacts are included.