[Feature]: Add Add OpenRC support for background service (Alpine Linux)

[Baz00k]

Summary

Add OpenRC support so zeroclaw can run as a background service on Alpine Linux

Problem statement

Alpine Linux uses OpenRC instead of systemd. zeroclaw’s Linux background service setup only supports systemd, so Alpine users cannot install a supported service that starts on boot and is managed consistently. This blocks lightweight server/container deployments that rely on Alpine.

Proposed solution

Provide OpenRC service support for zeroclaw:

• Add an OpenRC init script (e.g., /etc/init.d/zeroclaw)
• Auto detect which init daemon to use when setting up the zeroclaw service

Non-goals / out of scope

• No changes to core runtime behavior
• No systemd changes beyond existing support

Alternatives considered

No response

Acceptance criteria

• OpenRC init script available and functional on Alpine
• Documentation includes install/enable/start/stop instructions
• Service starts automatically on boot and runs zeroclaw reliably

Architecture impact

service

Risk and rollback

Risk: incorrect init script could cause failed boot service or missing logs.
Rollback: remove the OpenRC script and disable the service; existing systemd setup remains unchanged

Breaking change?

No

Data hygiene checks

• I removed personal/sensitive data from examples, payloads, and logs.
• I used neutral, project-focused wording and placeholders.

[theonlyhennygod]

Implemented in commit b3bd4fe. OpenRC support for Alpine Linux has been added with init script creation, auto-detection of init systems, and full start/stop/status/uninstall support for both systemd and OpenRC.

[Baz00k]

I appreciate the quick turnaround, hovewer current implementation does not work.
Running on a fresh alpine installation, latest commit, straight after bootstrap:

✅ Bootstrap complete.

Next steps:
  zeroclaw status
  zeroclaw agent -m "Hello, ZeroClaw!"
  zeroclaw gateway
zeroclaw-test:~# zeroclaw service install
✅ Installed systemd user service: /root/.config/systemd/user/zeroclaw.service
   Start with: zeroclaw service start
zeroclaw-test:~# zeroclaw service start
Error: Failed to spawn command

Caused by:
    No such file or directory (os error 2)
zeroclaw-test:~# rc-status
 * Caching service dependencies ...                                                         [ ok ]
Runlevel: default
 sshd                                                                                [  started  ]
 crond                                                                               [  started  ]
 networking                                                                          [  started  ]
 local                                                                               [  stopped  ]
Dynamic Runlevel: hotplugged
Dynamic Runlevel: needed/wanted
 localmount                                                                          [  started  ]
Dynamic Runlevel: manual
zeroclaw-test:~# cat /etc/alpine-release 
3.23.3

I opened a draft PR for the feature, where init daemon detection works.
Since OpenRC works "slightly" different than systemd, I have trouble setting up zeroclaw service with correct permisions and configs (the service is system scoped, not user scoped).

Any help is appreciated.