netbox/sandbox-fidelity-check.py (+4 assertions in tests/sandbox-seed, 22/22 PASS)

Counts and idempotency CANNOT prove a faithful seed. The region-scope bug proved
it: 17 of 90 prefixes silently lost their scope, every count still matched, and
re-runs were still perfectly idempotent. It was caught by LUCK on a spot-check
that happened to print 'site None'. This is that catch, made deliberate.

Method needs no new plumbing: prod-draft-dump.py is READ-ONLY, so point it at the
sandbox and diff the two JSON dumps FIELD BY FIELD.

RESULT: every shared object is field-level IDENTICAL to upstream, and the delta is
EXACTLY the expected D-115 additions (+edge role, +vr1-off1 site, +8 prefixes).
Nothing missing, nothing unexpected. The sandbox is a PROVEN baseline -- which is
what the later feed-back diff to production depends on.

Also de-misdirects docs/dc-dc-netbox-buildout-scope.md, which still told the next
person to run '--dc dc2' with DC2_V4_SUPERNET -- both of which the new guards now
REJECT by name. Its G5 recommendation (rename the APEX to vr1-dc1/vr1-dc2) is
marked SUPERSEDED: D-117 ruled the opposite. ORG_ULA_48 is now listed there as
UNASSIGNED and BLOCKING, not as a settled literal.

Disclosure: D-117 Option B is PARTIALLY executed -- the import path and the scope
doc are done; the $DC shell selector and the runbook DC prose are NOT. Recorded
in the ledger so 'D-117 ADOPTED' is not misread as 'fully renamed'.

repo-lint 0 fail. run-tests-all: ALL GREEN (55 harnesses).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013ZBxzAbmqwLW7jEmMG23Xw