security: CI egress filter — jobs reach the internet, never Veron/LAN

Measured: an unprivileged job container inside the CI dind could open SSH,
Ollama and dev servers on Veron (192.168.1.73) and the rest of the LAN,
WireGuard and Tailscale — lateral movement for any malicious dependency,
no escape needed. egress.sh (idempotent; windygit-ci-egress.service at
boot) hooks the jobs bridge: runner<->dind, replies, DNS and public
egress allowed; RFC1918, CGNAT, link-local and the host itself dropped.
Verified from a job container: 6/6 private targets blocked, DNS,
internet and the public forge OK.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

deploy/runner/windygit-ci-egress.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=Windy Git - CI egress filter (jobs reach the internet, never the LAN/host)
+After=docker.service
+Requires=docker.service
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+# The jobs network exists once the runner compose project is up; retry until it does.
+ExecStart=/bin/bash -c 'for i in $(seq 1 60); do /srv/windygit/src/deploy/runner/egress.sh && exit 0; sleep 5; done; exit 1'
+
+[Install]
+WantedBy=multi-user.target