pi-dispatch v1.6.1

A patch release for two defects live since v1.6.0, both in the worker. Full detail in the worker v1.6.1 notes.

• The wait check lease leaked. A superseded delivery, or one whose holder could not be verified, kept its check slot. At the shipped default of one slot that stopped every wait check on the worker until restart, while the failure surfaced as wait-expired / max-wait-unchecked and read like a capacity problem. Upgrade if you use run.waitFor with a profile condition.
• The run record no longer trusts the container's own object. tokens and session.reason came straight off the runner's exit line, so a container could put an arbitrary key or string into a record documented as PII-free by construction. Both are now rebuilt from closed lists, and a conformant image's record is byte-identical to before.

Worker and admin both move to 1.6.1; the receiver stays 1.4.0. The admin moves because it inlines the worker's modules at build time, so only a republish refreshes them.

2977 tests, 0 failures, every new assertion mutation-checked.