Report accepted queued commands and clear finished execution indices

[Jepson2k]

Queue readback includes accepted commands still waiting for planning or paused execution, and clears completed or cancelled indices. Supervised restart can therefore check whether the controller still has pending work. Completion waits inherit the parent branch’s exact command results and controller-session checks; unrelated concurrent tool completion cannot satisfy paused arm work.

Validation: real fake-serial regressions reproduced false completion of paused or cancelled arm work, late-response confusion, and missed controller restarts. Restart detection also watches independent status broadcasts when the command socket stops receiving after a peer reset. The latest change passes 16 controller/tool/lifecycle/error checks and 13 Commander pause, nested-skill, blended-stepping, recording, restart, and project-import workflows. Formatting and type checks pass. Query and acknowledgement receives preserve caller cancellation when a controller reply arrives concurrently, avoiding the Python 3.11 wait_for cancellation race observed in CI. The integration workflow cancels a query on arrival of a real controller reply and confirms subsequent queries still work. The latest CI run passes all twelve combinations of Linux, macOS, Windows and Python 3.11–3.14, plus lint. Each primary suite contains 314 cases (306 passed and eight separately executed examples skipped on Linux/macOS; 305 passed and the additional SIGKILL-only test skipped on Windows). All eight examples also pass in their separate job step on every combination.

Stacked on held-object geometry. Companion PRs: Commander, waldoctl, PAR6.