feat: Add High Availability setup roadmap and scripts

Created comprehensive HA roadmap with 6 phases:
- Phase 1: Warm standby (CURRENT - manual failover)
- Phase 2: Database replication
- Phase 3: Health monitoring
- Phase 4: Reverse proxy + floating IP
- Phase 5: Automated failover
- Phase 6: Geographic redundancy

Includes:
- Decision gates based on capital and stability
- Cost-benefit analysis
- Scripts for healthcheck, failover, DB sync
- Recommendation to defer full HA until capital > $5k

Secondary server ready at 72.62.39.24 for emergency manual failover.

Related: User concern about system uptime, but full HA complexity
not justified at current scale (~$600 capital). Revisit in Q1 2026.

ha-setup/trading-bot-ha.service

@@ -0,0 +1,24 @@
+[Unit]
+Description=Trading Bot v4 HA Failover Controller
+After=network.target docker.service
+Requires=docker.service
+
+[Service]
+Type=simple
+User=root
+WorkingDirectory=/home/icke/traderv4
+ExecStart=/bin/bash /home/icke/traderv4/ha-setup/failover-controller.sh
+Restart=always
+RestartSec=10
+StandardOutput=journal
+StandardError=journal
+
+# Logging
+SyslogIdentifier=trading-bot-ha
+
+# Security
+PrivateTmp=yes
+NoNewPrivileges=yes
+
+[Install]
+WantedBy=multi-user.target