Stale nightly lock cleanup + Sambuca queue unblock (fresh ownership check, authorized)

[tonykoop]

Part of #648. REPAIR steps 4-5: stale lock cleanup and Sambuca queue unblock.

Problem

runs/.nightly-cad.lock still names dead PID 914183 (no such process alive at the 2026-07-27 refresh), and the Sambuca queue job is blocked at run 20260719T150122Z-sambuca-historical-photo. The handoff forbids deleting the lock or mutating the queue until the ownership check is repeated at execution time AND Tony authorizes the supervised run.

Scope

• Re-run the redacted preflight immediately before acting: confirm no live process owns the lock PID at that moment (do not trust the 07-27 snapshot).
• With Tony's explicit authorization: clear/reset the stale lock, then requeue exactly run 20260719T150122Z-sambuca-historical-photo — preserving run id and any prior spend accounting per the resume contract (interrupted runs resume the same run id and retain prior spend).
• Capture before/after queue and lock state as an evidence comment.
• Nightly task remains Disabled throughout; no candidate is dispatched in this story.

Acceptance criteria

• Fresh ownership check performed and recorded before any mutation.
• Tony's authorization quoted/linked in the evidence comment.
• Lock cleared; queue shows the Sambuca job ready (not blocked), same run id, prior spend retained.
• No other queue entries mutated; no entrant invoked.

Execution environment: TONY-GATED (authorization required before any mutation) + WINDOWS-GATED (live queue/lock state on the Windows host).