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/TASKS.md

@@ -1,6 +1,6 @@
 # Current Tasks
 
-> **Last Updated**: 2025-11-17
+> **Last Updated**: 2025-12-18
 
 ## In Progress
 
@@ -8,6 +8,17 @@ None currently.
 
 ## Pending
 
+### Network Upgrade (Priority)
+See [NETWORK-UPGRADE-PLAN.md](NETWORK-UPGRADE-PLAN.md) for full details.
+
+- [ ] Order hardware (2× GiGaPlus 10G PoE, 2× U7 Pro)
+- [ ] Test Cat6 cable for 10G capability
+- [ ] Install switches and verify 10G backhaul
+- [ ] Deploy OPNsense VM on Elantris
+- [ ] Deploy UniFi Controller LXC
+- [ ] Configure VLANs and migrate services
+- [ ] Remove Asus mesh routers
+
 ### Media Organization
 - [ ] Verify Jellyfin can see all imported media
 - [ ] Clean up `.processing-loose-episodes` folder