docs: Add comprehensive network upgrade plan

- Created NETWORK-UPGRADE-PLAN.md with full topology and VLAN design
- Hardware: 2× GiGaPlus 10G PoE ($202), 2× U7 Pro ($378) = $580 total
- 10G backhaul between server closet and basement
- VLANs: Trusted (1), Servers (10), IoT (20), Guest (30)
- OPNsense VM for routing, UniFi Controller LXC for APs
- Updated TASKS.md with implementation checklist
- Updated DECISIONS.md with architecture rationale

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/CHANGELOG.md

@@ -14,6 +14,17 @@
   - Deployed via ProxmoxVE community helper script
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+### Planning
+- **Network Upgrade Plan**: Created comprehensive plan for network overhaul
+  - Replace Asus mesh with UniFi APs (U6 Enterprise existing + 2× U7 Pro)
+  - Add 10G backhaul between server closet and basement
+  - Hardware: 2× GiGaPlus 10G PoE switches (~$202), 2× U7 Pro (~$378)
+  - Total estimated cost: ~$580
+  - VLAN segmentation: Trusted (1), Servers (10), IoT (20), Guest (30)
+  - OPNsense VM on Elantris for routing/firewall
+  - UniFi Controller LXC for AP management
+  - See `docs/NETWORK-UPGRADE-PLAN.md` for full details
+
 ## 2025-12-15
 
 ### Frigate Migration & Upgrade