powerqueue v0.18.0

Fixed

• Bound shared launch failures with persistent project/global backoff. Isolated
  setup failures allow other work; repeated setup failures defer that project,
  and shared runtime or storage failures stop launching globally. Failed starts
  reserve no capacity or predicted budget. Doctor and events expose the failure,
  retry deadline and recovery; Rust stateful properties, Quint simulations and
  daemon integration tests cover isolation, restart, bounded attempts and recovery.

• Accept dead tmux panes whose process ID has been cleared after exit, so crash
  detection and retry continue to work on current macOS tmux versions.

• Update the locked rustls dependency to 0.23.46 to resolve the security
  advisories reported by CI.

• Recover abandoned starting tasks after launch persistence failures or daemon
  restarts using normal attempt limits and backoff. Recovery preserves work,
  rejects stale task/session observations, and waits for surviving setup processes
  or unrecorded agents. Doctor explains the hold and the saved tmux destination;
  doctor --fix no longer interrupts starting tasks.

Added

• Quint simulation and event replay cover dependency blocking/unblocking and PR
  handoff, session release, review relaunch and merge, including per-round crash
  allowances and paused review watches. Synthetic rejection tests check invalid
  ordering; existing v0.14.0 event logs work without a daemon upgrade. Human
  blockers, containers, PR adoption, live-session retry release, and unsupported
  review/relay changes still end the affected prefix. Dependency holds reject
  live sessions and check the logged previous state against the model.