Run release benchmarks under caffeinate

[deverman]

Outcome

A release operator can start the 1.5-hour release benchmark unattended on the first attempt without adding host-sleep detection code.

What changed

• Run the release profile under caffeinate -is from the start.
• Require AC power and an open MacBook lid; display sleep or locking remains fine.
• Explicitly allow starting the suite before an overnight unattended window.
• Preserve fail-closed evidence and the one bounded retry rule.

Why

Issue #193 proposed new clock and power-state classification machinery after one sleep-interrupted certification run. A controlled operating rule removes the known cause with less code and maintenance.

Validation

• caffeinate -is /usr/bin/true
• swift run focusrelay-dev validate --impact docs
  • whitespace check passed
  • local Markdown links passed

Related to #193.