Restructure docs: archive VLAN migration, update IPs to VLAN 10

Major documentation cleanup after VLAN migration completion:
- Archive 12 VLAN project docs to archive/vlan-migration/
- Archive 5 done WIP docs (VLAN proposals, AI stack, Fossorial, DNS backup)
- Create standing reference docs 08-DNS-ARCHITECTURE and 09-TAILSCALE-VPN
- Renumber docs to clean 01-09 sequence with merged CHANGELOG
- Update all active docs from stale 192.168.31.x to current VLAN 10 IPs
- Fix CSS1 (.10.9→.10.3) and ZX1 (.10.7→.10.4) IPs in hardware inventory
- Clean 06-VLAN-DEVICE-ASSIGNMENT: remove migration columns/sections, fix VLAN 25 subnet

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/wip/GITOPS-CONTAINERS.md

@@ -104,7 +104,7 @@ pipeline:
     when:
       path: configs/xtrm-n5/**
     commands:
-      - ssh root@192.168.31.2 "cd /path && docker compose up -d"
+      - ssh root@192.168.10.20 "cd /path && docker compose up -d"
     secrets: [ssh_key]
 
   deploy-n1: