Capture action poll consumes the whole lease, leaving no budget for cleanup proof #866

Problem

#865 made capture scene actions poll for their UIA target until the worker lease deadline. In live run C4 (e7ca82f2) the target never appeared (see #848), so the poll consumed the entire lease, ending at 01:35:48Z with the deadline at 01:35:48.72Z.

The supervisor then had no remaining budget to read the process journal:

• JournalUnavailable at sequence 10;
• firstOpen=NOT_ATTEMPTED because the deadline was exhausted;
• workerExitCode and journalFinalBinding are null.

As a result, the official lease release was CLEANUP_UNPROVEN rather than a proven clean release. A read-only host check after the run found no surviving processes under the run root, but the harness itself could not prove that.

Ask

Give per-action UIA waits their own bounded budget, separate from the reserve the supervisor needs for teardown, journal reading and cleanup proof. For example, cap each action wait and/or end it at the lease deadline minus an explicit cleanup reserve.

Add a test showing that a never-appearing action target still ends with a proven clean release (FAILED_ZERO_SURVIVORS), not CLEANUP_UNPROVEN.

Refs #848, #865