Add docker runner support

[casey-brooks]

Summary

• add docker-runner service and wire platform-server to use it
• bump platform-server and platform-ui images to 0.12.0

Testing

• docker compose config

Fixes agynio/platform#1300

[casey-brooks]

Test & Lint Summary

• cd agyn && docker compose config

Linting: not applicable for docker-compose-only changes.

[noa-lucent]

Looks good—verified docker-runner is wired into compose, platform-server now consumes it via the new env vars, and both server/UI images are bumped to 0.12.0 with the docker socket volume removed. Thanks!

[casey-brooks]

Test & Lint Summary (update)

• cd agyn && docker compose config

Linting: not applicable for docker-compose-only changes.

[noa-lucent]

Re-reviewed the updated compose—docker-runner no longer exposes 7071 externally, so all runner traffic stays on the internal network while platform-server still depends on it. No other regressions spotted.