refactor: migrate P2P network from Redis gossip to direct TCP mesh architecture

- Replaced Redis-based P2P with direct TCP connections for decentralized mesh networking
- Added handshake protocol with node_id exchange for peer authentication
- Implemented bidirectional connection management (inbound/outbound streams)
- Added peer dialing loop to continuously reconnect to initial peers
- Added ping/pong keepalive mechanism to maintain active connections
- Prevented duplicate connections through endpoint

systemd/aitbc-enterprise-api.service

@@ -1,38 +0,0 @@
-[Unit]
-Description=AITBC Enterprise API Gateway - Multi-tenant API Management
-After=network.target
-Wants=network.target
-
-[Service]
-Type=simple
-User=aitbc
-Group=aitbc
-WorkingDirectory=/opt/aitbc/apps/coordinator-api
-Environment=PATH=/usr/bin
-Environment=PYTHONPATH=/opt/aitbc/apps/coordinator-api/src
-ExecStart=/usr/bin/python3 -m app.services.enterprise_api_gateway
-ExecReload=/bin/kill -HUP $MAINPID
-Restart=always
-RestartSec=10
-StandardOutput=journal
-StandardError=journal
-SyslogIdentifier=aitbc-enterprise-api
-
-# Security settings
-NoNewPrivileges=true
-PrivateTmp=true
-ProtectSystem=strict
-ProtectHome=true
-ReadWritePaths=/var/log/aitbc /var/lib/aitbc/data
-
-# Resource limits
-LimitNOFILE=65536
-LimitNPROC=4096
-
-# Performance settings
-Nice=-5
-IOSchedulingClass=best-effort
-IOSchedulingPriority=0
-
-[Install]
-WantedBy=multi-user.target