Mount docker and node binaries from arrsstack host into act_runner container

compose-snippets/act_runner.yml

@@ -1,9 +1,10 @@
 # act_runner — Gitea Actions self-hosted runner
-# Deploy on the machine running Gitea (same host).
+# Runs on arrsstack (10.0.0.104). Gitea is on a separate machine (10.0.0.102).
 # Registers at instance level — services all repos.
 #
-# Uses host execution mode — jobs run directly on the host machine,
-# so Docker commands work natively without socket passthrough complexity.
+# host mode: jobs run inside the act_runner container.
+# docker and node binaries are mounted from arrsstack's host filesystem
+# so workflow steps can call docker build, docker push, etc.
 #
 # Setup:
 #   1. Gitea → Site Administration → Actions → Runners → Create Runner → copy token
@@ -19,10 +20,11 @@ services:
       - GITEA_INSTANCE_URL=https://git.thewichersfamily.com
       - GITEA_RUNNER_REGISTRATION_TOKEN=${RUNNER_TOKEN}
       - GITEA_RUNNER_NAME=homelab-pi5
-      # host mode: jobs run directly on this machine — Docker is available natively
       - GITEA_RUNNER_LABELS=ubuntu-latest:host,ubuntu-22.04:host
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock
+      - /usr/bin/docker:/usr/bin/docker:ro
+      - /usr/bin/node:/usr/bin/node:ro
       - act_runner_data:/data
 
 volumes: