DOCFIX-174: fix self-inflicted false positive in ledger-scan.sh next-free scan ...

DOCFIX-173's own changelog narrated its {3}->{3,} regex fix using a literal
illustrative example ("DOCFIX-1004"), which the widened regex then matched
as a real assignment -- inflating DOCFIX next-free from 174 to 1005.
Reworded the illustrative examples in prose, added a reproduc-line
exclusion to nextfree_mentions() as defense-in-depth, and added a
regression fixture to the test harness (37/37 PASS).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QrcJx8TUar7pYAvpGJw57A

addendum 33: script-quality fix batch DOCFIX-112..117 -- anti-escalation guard fail-closed (SECURITY), tenant-offboard hardening cluster, validate/juju-spaces fail-opens, pipefail sweep, guard-hook extension; deferred-findings register; ledger REMAINING-OPEN-WORK block ...

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QFdCdEuxynmM8Q6HichbHn

addendum 28: operator-away batch integrated -- DOCFIX-098..105 (H4 drift detector, offboard orphan sweep + E0 guard, handover pack, cloud-snapshot, tenant-acceptance harness, lint L7 sweep rule, ledger-scan 099-boundary fix) ...

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QFdCdEuxynmM8Q6HichbHn

clearing queue

patches