[Feature] Add Support for Older Docker Socket API Versions

[j-heffron]

Description

To start with a use case, My current deployment of Headplane is on an Opensuse Leap 16.0 system running the latest shipped version of Podman (5.4.2) by distro. This version implements an equivalent socket API of 1.41. #497 and consequently version 0.7.0 breaks Docker integration on my deployment.

Formal support for API 1.41 or older or at least a way to disable the changes brought in the pull request in the upstream package would be nice to have.

[pullfrog]

Plan: Add support for older Docker socket API versions

The current DockerIntegration in app/server/config/integration/docker.ts hard-codes Docker API 1.44 for both discovery (/v1.44/containers/json) and restart (/v1.44/containers/{id}/restart), and refuses to run if the daemon reports an older ApiVersion (e.g. Podman 5.4.2 implementing API 1.41). Issue #589 asks for formal support of API 1.41+ or a way to disable the 1.44 requirement.

Proposed approach

1. Expose the required Docker API version as a config option (e.g. docker.api_version) so users can opt into an older API when their runtime requires it.
2. Default to 1.44, preserving current behavior for existing installs.
3. Use the configured API version in all versioned API calls (containers/json, containers/{id}/restart) instead of the hard-coded constant.
4. Update validation to compare the daemon’s reported ApiVersion against the configured version rather than the hard-coded 1.44.
5. Update tests in tests/integration/platform/docker.test.ts to cover a custom API version path, and adjust the hard-coded /v1.44 request path in the restart test.
6. Update documentation in docs/install/docker.md to describe the new option and any compatibility notes for Podman users.

Open questions

• Is a simple string config field acceptable, or should we keep a known minimum supported version and warn when it is below 1.44?
• Do we want to allow an explicit auto value that uses the daemon’s reported ApiVersion, or just a concrete override?

I can proceed with implementation once this plan is approved.

Task list (1/5 completed)

• Read AGENTS.md and repo learnings for context
• Fetch issue [Feature] Add Support for Older Docker Socket API Versions #589 details from GitHub
• Investigate Docker socket API usage in codebase
• Assess feasibility and formulate actionable plan
• Post plan as progress comment on issue

  ^{｜ Implement plan ➔ ｜ View workflow run ｜ via Pullfrog ｜ Using Kimi K2 (free via Pullfrog for OSS) ｜ 𝕏}

[linear-code]

HP-563