Run the agent on Podman through the Docker-compatible API

The agent talks to the container runtime through the Docker API and assumes Docker's dialect of it in several places. Podman serves the same API but differs in what it puts in the responses and in what it accepts in requests, so each of those assumptions fails separately. This epic collects them.

Two deployment shapes are in view: a rootful Podman socket with the agent running as root, which is where the first reports came from, and a rootless socket with the agent running unprivileged, which is the reason for choosing Podman in the first place. They exercise different code paths — the cgroup statistics mode is only reachable in the former.

JIRA Issue: BA-7382

Start by mapping the agent's Docker API interactions and comparing the requests and responses that differ under Podman. Check both rootful and rootless socket deployments, including the cgroup statistics path. Done means the agent operates correctly through Podman's Docker-compatible API in both deployment shapes.

Written by the indexing model from the issue text.