feat: Add Docker Compose release bundle and align deployment docs

[javaChip56]

Summary

• Add Docker support for the dashboard with Linux and Windows Compose configurations.
• Add configurable host port support through APIHEALTHDASHBOARD_PORT.
• Extend the release workflow to validate Compose files, build and smoke-test the Linux container flow, and publish Docker Compose release bundles with checksums.
• Add Docker usage documentation and update README status/deployment notes to match the current implemented surface.

Validation

• dotnet test .\ApiHealthDashboard.sln -c Release
• docker compose -f docker-compose.yml config
• docker compose -f docker-compose.windows.yml config
• docker compose -f docker-compose.yml build
• Started the Linux Compose app with APIHEALTHDASHBOARD_PORT=18080 and verified / returned HTTP 200

Notes

• The Linux container flow is locally validated.
• The Windows container Compose file validates, but a Windows container build/run was not executed locally because the Docker engine was in Linux mode.