flowjet 2.1.6 — ArcBox sandbox survives recycles, crashes and restarts

Fixed

• ArcBox tool sandboxes stay usable across recycles, crashes and restarts.
  The manager trusted its in-memory lease map, and the agent graph pinned its
  sandbox id at build time, so a guest that died behind a still-ready daemon
  record (host sleep, idle recycle, daemon restart) left the worker talking to a
  corpse: every file/shell tool failed and the agent reported an empty
  workspace even though the host tree was fully staged. open_workspace now
  probes readiness once per turn — a control-plane info() tier that catches a
  record outliving its VM plus terminal states, then a guest round-trip that
  catches a wedged guest — and kills, drops and replaces a lease that fails.
  Every new guest, whether spawned or adopted, is seeded from the host
  workspace, and in-flight run counts carry over so peer open/close pairs stay
  balanced. The agent cache key is now workspace + sandbox id, so a respawn
  rebuilds the graph against the live guest.
• Crash and restart recovery. VMs are created with a labelled orphan
  deadline (idle_timeout + on_idle=kill) that the reaper re-arms every 60 s,
  so a process that dies leaves nothing behind — the daemon reaps it, with no
  cross-process coordination and no startup kill-list. On first use the manager
  scans owner-scoped sandboxes and adopts a surviving VM, pulling guest state to
  the host before pushing (recovering a crashed turn's artifacts) instead of
  spawning a duplicate; a failed create reconnects the client and retries once.
• Every control-plane RPC is bounded (kill/set_lifecycle 15 s, connect
  by connect_timeout). The SDK's per-RPC deadline is opt-in and was
  unconfigured: one wedged call stalled the reaper loop, and a stalled heartbeat
  reads to the daemon exactly like a dead owner — which gets healthy, in-use VMs
  reaped at their deadlines.

Changed

• sandbox.orphan_timeout_seconds defaults to max(900, 3 × idle_timeout_seconds)
  instead of a fixed 900, and an explicit value is validated only when the
  sandbox is enabled — existing configs keep parsing unchanged. New keys:
  recover_orphans (adopt surviving VMs after a restart) and owner (label
  namespace, env FLOWJET_SANDBOX_OWNER) so planes sharing one ArcBox daemon
  never adopt or reap each other's sandboxes. See RFC-005 §5.1/§5.2.