network: add hub registration, Redis persistence, and federated mesh join protocol

- Change default P2P port from 7070 to 8001 in config and .env.example
- Add redis_url configuration option for hub persistence (default: redis://localhost:6379)
- Implement DNS-based hub registration/unregistration via HTTPS API endpoints
- Add Redis persistence for hub registrations with 1-hour TTL
- Add island join request/response protocol with member list and blockchain credentials
- Add GPU marketplace tracking (offers, bids, providers) in hub manager
- Add

systemd/aitbc-marketplace.service

@@ -10,7 +10,7 @@ Group=root
 WorkingDirectory=/opt/aitbc
 Environment=PATH=/usr/bin:/usr/local/bin:/usr/bin:/bin
 Environment=NODE_ID=aitbc
-Environment=MARKETPLACE_PORT=8002
+Environment=MARKETPLACE_PORT=8007
 Environment=WORKERS=1
 Environment=PYTHONPATH=/opt/aitbc/services
 EnvironmentFile=/etc/aitbc/production.env

systemd/aitbc-web-ui.service

@@ -1,38 +0,0 @@
-[Unit]
-Description=AITBC Web UI Service (Port 8016)
-Documentation=https://docs.aitbc.bubuit.net
-After=network.target aitbc-coordinator-api.service
-Wants=aitbc-coordinator-api.service
-
-[Service]
-Type=simple
-User=aitbc
-Group=aitbc
-WorkingDirectory=/opt/aitbc/apps/blockchain-explorer
-Environment=PATH=/opt/aitbc/venv/bin:/usr/bin
-Environment=PYTHONPATH=/opt/aitbc/apps/blockchain-explorer
-Environment=PORT=8016
-Environment=SERVICE_TYPE=web-ui
-Environment=LOG_LEVEL=INFO
-ExecStart=/opt/aitbc/venv/bin/python -m http.server 8016 --bind 127.0.0.1
-ExecReload=/bin/kill -HUP $MAINPID
-Restart=always
-RestartSec=10
-StandardOutput=journal
-StandardError=journal
-SyslogIdentifier=aitbc-web-ui
-
-# Security settings
-NoNewPrivileges=true
-PrivateTmp=true
-ProtectSystem=strict
-ProtectHome=true
-ReadWritePaths=/var/log/aitbc /var/lib/aitbc/data /opt/aitbc/venv
-LimitNOFILE=65536
-
-# Resource limits
-MemoryMax=1G
-CPUQuota=100%
-
-[Install]
-WantedBy=multi-user.target