Multi-interface management, topology view, performance tuning, precompiled CSS

- Interface model with per-interface subnet/port/keys; import/adopt existing wg-quick configs (key-less imported peers, optional key rotation), cascade delete
- Split wireguard.py into a package (keys via cryptography X25519, status, addressing, conf parse/render, sync, host tuning)
- ECharts horizontal topology view (interface -> peers -> site subnets)
- Advanced options: MTU, MSS clamping, FwMark/Table, custom PostUp/PostDown, per-peer keepalive override
- Runtime settings (sample interval/retention, online threshold, UI refresh) with traffic sample pruning; host tuning (UDP buffers, backlog, GRO forwarding)
- Precompiled Tailwind CSS replacing Play CDN runtime (fixes FOUC); stable table layout and diffed polling renders
- Host network mode in compose; NAT/isolation iptables moved into app sync

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

.gitignore

@@ -4,4 +4,5 @@ __pycache__/
 data/
 wg-admin-data/
 wg-config/
+volumes/
 .env