Adds PRD 0015, the second remediation engine in the stuck-agent
recovery flow (overview in PRD 0012, foundation in PRD 0013). Wires
the pipelock block path with restart-based reload: supervisor writes
the new allowlist on approval and restarts pipelock, proactive
pipelock edit TUI verb, pipelock audit log filled in. SIGHUP reload
for pipelock is deferred to a follow-up.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
