DOCFIX-163: Office1-local network module + OPNsense edge ownership (gaps #12+16) ...

New opentofu/modules/office1-network (dc-planes-shaped, one shared network
instead of six), instantiated for real in main.tf -- deliberately not a
reused host bridge, since that would live outside OpenTofu's D-103
inventory and break the virsh net-list --all completeness check used
throughout the runbooks. Decided gap #16: Office1 gets its own OPNsense
edge (a fourth site), owned by Stage 2's runbook (new Step 4b). Found a
deeper cross-site gap while wiring the edge's WAN side (no per-site
ISP-uplink network exists for ANY site yet, DC1/DC2 included) -- logged as
new gap #17 rather than defaulted to a mesh-link, which would contradict
D-100's management-only ruling for those legs.

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

DOCFIX-154/155/156: Stage 2/3/5 runbooks -- Office1 standup, DC substrate, per-DC bundle ...

Three DC-DC runbooks authored in parallel this evening:
- Stage 2 (Office1 headend standup): MAAS-region/NetBox/GitBucket/Tailscale,
  each VM-creation step forking an explicit OpenTofu-blocked vs manual-debt
  path rather than picking one silently. Flags a real gap: no Office1-local
  network is modeled in opentofu/.
- Stage 3 (OpenTofu builds each DC substrate): DC1-first, DC2 hard-gated on
  NetBox literals. Walks every open decision (node sizing, MAAS zone/pool,
  config.xml tokens, netem params) and stops rather than inventing values.
- Stage 5 (Juju controller + bundle, per DC): describes adapting the
  existing phase-01..08 loop to run twice, not duplicating it. Mandates the
  $DC selector convention (DOCFIX-151) before every adapted command block.
  Surfaces the undesigned IPv6 family-matrix overlay as blocking work.

All three: not yet executed (prep-only session, no live infrastructure
reachable tonight); repo-lint 0 fail/1 documented warn.

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