Replace briefing system with fancy CLI status display panel

- Removed hourly news briefing system (briefing service/timer)
- Added tty_status_display.py: real-time status panel showing dual nail status
  - Temperature, setpoint, error, PID output with visual bar
  - Flight mode and phase badges with color coding
  - PID coefficients and integral/derivative values
  - Safety status indicators
  - Continuous color-coded display with ANSI formatting
- Added pinail-status.service: systemd service for status display
  - Runs as root with direct TTY output to /dev/tty1
  - Auto-restart on failure, requires pinail2.service
  - Logs errors to /tmp/status_display.log
- Deployed and verified running on Pi (service active)

piNail2/pinail-status.service

@@ -0,0 +1,20 @@
+[Unit]
+Description=piNail2 Status Display Panel
+After=pinail2.service network-online.target
+Wants=network-online.target
+Requires=pinail2.service
+
+[Service]
+Type=simple
+User=root
+WorkingDirectory=/home/pi/piNail2
+ExecStart=/usr/bin/python3 /home/pi/piNail2/tty_status_display.py
+Restart=always
+RestartSec=5
+StandardOutput=tty
+StandardError=file:/tmp/status_display.log
+TTYPath=/dev/tty1
+SyslogIdentifier=pinail-status
+
+[Install]
+WantedBy=multi-user.target