Fix network boot issues and add power management configuration

- Resolve SSH lockout after reboot caused by systemd lid switch suspend
- Add systemd-logind configuration to disable lid switch handling
- Add NetworkManager configuration for static IP and power management
- Update network troubleshooting documentation with complete solution
- Include diagnostic commands and deployment steps

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

docs/network-security.md

@@ -443,6 +443,80 @@ ip link set wlp2s0 master br0
 - External: ak-homelab.duckdns.org ✅
 - SSH: Port 2222 ✅
 
+## Network Boot Issues Troubleshooting
+
+### Problem 1: Network not available after reboot until GUI login
+
+**Initial diagnosis**: Thought to be NetworkManager sleep behavior.
+
+**Actual root cause**: System auto-suspend due to closed laptop lid (`HandleLidSwitch=suspend`).
+
+**Symptoms**:
+- SSH inaccessible after reboot 
+- Network comes up only when laptop lid is opened
+- System logs show "Suspending..." followed by "Lid opened"
+
+**Solution Applied**:
+1. **systemd-logind configuration**: Disable lid switch handling for headless server operation
+2. **Static IP configuration**: Eliminate DHCP negotiation delays  
+3. **High connection priority**: Ensure ethernet connects first
+
+**Configuration files created**:
+
+`/etc/systemd/logind.conf.d/01-server-logind.conf`:
+```ini
+[Login]
+# Disable all power management triggers for headless server
+HandleLidSwitch=ignore
+HandleLidSwitchExternalPower=ignore  
+HandleLidSwitchDocked=ignore
+
+# Prevent automatic suspend/hibernate
+IdleAction=ignore
+
+# Keep system running even when no users logged in
+KillUserProcesses=no
+```
+
+**NetworkManager commands**:
+```bash
+nmcli connection modify "Wired connection 2" connection.autoconnect-priority 10
+nmcli connection modify "Wired connection 2" ipv4.method manual ipv4.addresses 192.168.0.100/24 ipv4.gateway 192.168.0.1 ipv4.dns "84.2.44.8 84.2.46.8"
+```
+
+**Deployment**:
+```bash
+sudo cp config/systemd/01-server-logind.conf /etc/systemd/logind.conf.d/
+sudo systemctl restart systemd-logind
+sudo cp config/networkmanager/01-homelab.conf /etc/NetworkManager/conf.d/
+sudo systemctl reload NetworkManager
+```
+
+### Diagnostic Commands
+
+**Check system power state**:
+```bash
+systemctl status systemd-logind  # Check for suspend/lid events
+loginctl show-session           # Current power management settings
+```
+
+**Check network connectivity**:
+```bash
+systemctl status NetworkManager
+nmcli device status
+nmcli connection show "Wired connection 2"
+ip addr show enp4s0
+```
+
+**Monitor boot process**:
+```bash
+journalctl -b -u NetworkManager    # Network startup logs
+journalctl -b -u sshd             # SSH service logs  
+journalctl -b -u systemd-logind   # Power management events
+```
+
+**Result**: ✅ **RESOLVED** - SSH accessible immediately on boot, lid closure no longer suspends system.
+
 **Network Interface Identification:**
 - **enp3s0f0**: First ethernet port (98:fa:9b:f1:06:d5)
 - **enp4s0**: Second ethernet port (98:fa:9b:f1:06:d4) ← **Use this one**