feat(rego-tunnel): Add Dockerfile and build scripts for cisco-vpn image

Includes:
- Dockerfile for native Cisco Secure Client in Docker
- Build scripts (init-vpn.sh, startup-vnc.sh, vpn-connect.sh)
- VNC configuration (xstartup, vnc.service)
- build.sh for manual image builds
- README documenting the architecture

Note: cisco-secure-client-full.tar.gz is gitignored (large binary)
Copy it from ~/projects/cisco-vpn/build/ before building.

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

apps/rego-tunnel/build/build.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+# Build and push the Cisco VPN Docker image
+# Run this from the build directory
+
+set -e
+
+IMAGE_NAME="${IMAGE_NAME:-git.alexzaw.dev/alexz/cisco-vpn}"
+IMAGE_TAG="${IMAGE_TAG:-latest}"
+
+echo "Building ${IMAGE_NAME}:${IMAGE_TAG}..."
+
+docker build -t "${IMAGE_NAME}:${IMAGE_TAG}" .
+
+echo ""
+echo "Build complete!"
+echo ""
+echo "To push to registry:"
+echo "  docker push ${IMAGE_NAME}:${IMAGE_TAG}"
+echo ""
+echo "To test locally:"
+echo "  docker run -d --privileged --cgroupns=host -v /sys/fs/cgroup:/sys/fs/cgroup:rw --cap-add=NET_ADMIN --device=/dev/net/tun -p 6080:6080 ${IMAGE_NAME}:${IMAGE_TAG}"