chore: bump mc-observability to v0.7.1

[ish-hcc]

Bump mc-observability images to 0.7.1, matching the upstream v0.7.1 tag, and restore the manager port mapping.

• docker-compose.yaml: mc-observability images 0.7.0 -> 0.7.1
• docker-compose.yaml: restore the ports block of mc-observability-manager (18080 -> MC_OBSERVABILITY_MANAGER_PORT). It was removed together with the front ports in 7edd0eb, but only the front is served through the nginx proxy, so the manager API was no longer reachable from the host.
• mc-observability-infra ansible: sync the agent install files changed in v0.7.1 (install rsyslog when missing instead of hanging, swap podman binaries in by rename). This directory is bind-mounted, so the image bump alone does not apply them.