v0.20.2

Added

• A hang policy for out-of-process workers (opt-in: hang_after_idle_s on a worker-backed adapter).
  While a problem is in flight, the worker's process tree is sampled from /proc; less than
  hang_idle_cpu_s CPU seconds (default 1) over hang_after_idle_s seconds of wall is a hang, and so is a
  missed hard timeout. The problem is retried once in a fresh worker and a second hang fails it. Every
  hang is written to hang_log (JSON lines: problem, attempt, kind, seconds, CPU in the window, outcome)
  and counted in the row's worker_hangs. Hang restarts do not spend max_restarts, which stays the
  budget for crashes. Without the key nothing changes.
• PySR on the whole suite, on the reference machine. scripts/make_pysr_suite_config.py writes one
  experiment per catalog with the data sources and runners of a Flash-ANSR scaling config, PySR with
  upstream defaults, the iteration count as the ladder, and the hang policy on (60 s);
  scripts/run_timing_ladder.py --full-suite runs such a config unit by unit on whole catalogs, and the
  solomon timing queue runs it (three runs, RUN_PYSR_SUITE=0 skips them).
• scripts/stop_timing_queue.sh: stops the timing queue without corrupting its marks (the queue first,
  processes matched by their exact command, any mark written while stopping rolled back).