v0.6.0

Added

• Added start_exec for asynchronous background execution through a unified in-process Exec Job Manager.
• Added queued admission with independent sync, async, and global running-slot limits plus a bounded queue.
• Added incremental get_exec_status stdout/stderr reads with independent cursors, bounded long-polling, pagination indicators, and permanent-log-truncation indicators.
• Added bounded per-job retained logs, job retention/GC controls, queue/admission metrics, and graceful shutdown of active background jobs.

Changed

• Refactored exec to submit through the same ExecutionSpec and runner lifecycle as start_exec, then wait internally for terminal completion while preserving the synchronous public result.
• Runtime timeout now starts when a queued job enters execution rather than while it waits for admission.
• list_active_execs now reports queued and running jobs together with sync/async/global capacity and queue position.
• cancel_exec terminalizes queued jobs immediately and preserves immutable terminal states; running cancellation continues to terminate the full process group.
• Job metadata, history, list output, and lifecycle logs never retain raw environment values; retained Job Manager output additionally redacts submitted environment values.

Security

• Preserved bounded process-group termination and added explicit regression coverage for manual cancellation of asynchronous commands with background children.
• Added hard limits for queue length, retained job logs, status output pages, and wait_seconds (maximum 30 seconds).