Operator ruling: rename the DC numbers to match the NetBox apex; the office
keeps its number (Office1 -> new site vr1-off1, so nothing deployed changes).

netbox/dc-dc-prefixes-import.py:
  --dc dc1|dc2  ->  --dc dc0|dc1, bound to the APEX slugs measured live:
    dc0 -> vr1-dc0 (2602:f3e2:f02::/48)    dc1 -> vr1-dc1 (f03::/48)
  It previously mapped dc1 -> vr1-dc1 while treating f02::/48 as dc1, i.e. it
  would have written VR1 DC0's prefixes to the OTHER DC's site.
  Now DRY BY DEFAULT with --commit (it used to write with no flag at all).
  A dry run against a FRESH NetBox now plans the site too (_PlannedSite) rather
  than bailing with 'no site id' -- previewing an empty apex is the whole point.
  DC2_V4_SUPERNET is REJECTED BY NAME (retired) rather than silently ignored.
  Every 'DCn' in prose is region-qualified: 'DC0' meant VR0's rehearsal DC in
  some sentences and VR1's first DC in others. No sed could have caught that.

tests/dc-dc-prefixes-import/: 73 checks ALL PASS, incl. regression guards that
  the dry run creates NOTHING, that --dc dc0 never touches vr1-dc1, and that the
  invented vr1-dc2 site is never created.

FOUND, RECORDED, NOT YET FIXED (D-117 amendment): scripts/lib-net.sh carries a
SECOND, colliding $DC namespace where dc0 already means VR0's DC0. Renaming
VR1's dc1->dc0 there would collide with VR0. Proposed fix: region-qualify the
shell selector to the apex slugs (vr0-dc0/vr1-dc0/vr1-dc1). Does not block the
import; the two selectors are NOT interchangeable meanwhile.

repo-lint 0 fail. run-tests-all: ALL GREEN (53 harnesses).

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