rego-tunnel: use eth0 for container IP detection

The vpn_static-rego network is on eth0, not eth1.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/rego-tunnel/vpn_scripts/start.sh

@@ -28,8 +28,8 @@ get_windows_ip() {
 }
 
 get_container_ip() {
-  # Get container's external IP (tipi_main_network - eth1)
+  # Get container's external IP (vpn_static-rego - eth0)
-  ip -4 addr show eth1 2>/dev/null | awk '/inet / {print $2}' | cut -d/ -f1
+  ip -4 addr show eth0 2>/dev/null | awk '/inet / {print $2}' | cut -d/ -f1
 }
 
 (