feat(docker): replace Packer snapshots with Docker-based agent delivery (#2206)

* feat(docker): replace Packer snapshots with Docker-based agent delivery

Docker images on GHCR are public and cross-account, unlike DO snapshots
which are private/account-scoped. Cloud-init installs Docker + pulls the
agent image during boot. The install step extracts pre-built binaries via
`docker cp` and falls back to normal install if unavailable.

- Add Dockerfiles for all 7 agents (claude, codex, openclaw, opencode,
  kilocode, zeroclaw, hermes)
- Convert docker.yml to matrix build for all agents
- Add tryInstallFromDocker() shared helper with Docker-first install
- Add Docker pull to DigitalOcean cloud-init userdata
- Remove Packer snapshot pipeline, lookup, and SSH-only wait
- Remove packer/ directory (HCL templates, tier scripts, agents.json)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* security: address review findings in docker agent delivery

- Add agentName validation regex (/^[a-z0-9-]+$/) in digitalocean.ts
  before interpolation into cloud-init script
- Quote dockerImage variable in all docker command strings in
  agent-setup.ts to prevent command injection
- Restrict docker cp to specific known directories (.claude, .bun,
  .local, .npm, .cargo, .opencode) instead of blanket /root/.

Agent: pr-maintainer
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: B <6723574+louisgv@users.noreply.github.com>

.github/workflows/docker.yml

@@ -6,7 +6,7 @@ on:
     paths:
       - "sh/docker/**"
   schedule:
-    # Daily: pick up new openclaw releases
+    # Daily: pick up new agent releases
     - cron: "0 6 * * *"
   workflow_dispatch:
 
@@ -15,8 +15,12 @@ permissions:
   contents: read
 
 jobs:
-  build-openclaw:
+  build:
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        agent: [claude, codex, openclaw, opencode, kilocode, zeroclaw, hermes]
     steps:
       - uses: actions/checkout@v4
 
@@ -29,6 +33,6 @@ jobs:
       - uses: docker/build-push-action@v6
         with:
           context: .
-          file: sh/docker/openclaw.Dockerfile
+          file: sh/docker/${{ matrix.agent }}.Dockerfile
           push: true
-          tags: ghcr.io/openrouterteam/spawn-openclaw:latest
+          tags: ghcr.io/openrouterteam/spawn-${{ matrix.agent }}:latest