DOCFIX-138: S8b -- centralize KEYSTONE_VIP default into lib-net.sh (single source of truth) ...

The keystone endpoint literal 10.12.4.50 was the default in 6 scripts (3 forms); now
all reference lib-net.sh KEYSTONE_VIP_DEFAULT (hard-rule #3). Sourced lib-net where
absent (verified source-safe). Each stays env-overridable. Resolve-checked; gauntlet
39/39, lint 0 fail (L7 re-recorded). S8 fully done (S8a+S8b); S8c won't-do.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

DOCFIX-134: S8a -- FIP pool literals to lib-net.sh (single source of truth) ...

D-003 FIP pool (10.12.5.0-10.12.7.254) was hardcoded in phase-04-network-create
(env-overridable) and -verify (pinned). Both already source lib-net.sh; added
FIP_POOL_START/END there and referenced them. Gauntlet 39/39. S8b (KEYSTONE_VIP,
needs sourcing into client-critical scripts) + S8c (python cross-source) deferred
for operator decision -- bigger than the S estimate.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

D-060: revert to Pattern A; supersede D-057/D-058 ...

Revert provider NIC to Pattern A (MAAS-built OVS br-ex) on the existing D-052/D-053 scheme. bundle.yaml clean bf7de5a checkout (provider-public x11, VIP triple .4/.8/.12, all 4 br-ex MACs); lib-net.sh + carve back to D-052/D-053; NEW provider-bundle-check.py gate; standup retargeted; teardown.sh + teardown runbook updated. Retire: phase-00-maas-recidr.sh, provider-vip-standup.sh, d057-bundle-check.py, and the 3 provider-vip/reconfigure runbooks.

Provider VIP carve updates

MAAS script updates

Adding scripts