Show plugin settings in system property list

[amarkdotdev]

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update

Motivation and Context

container system property list showed core system configuration but omitted plugin-scoped values from [plugin.*] sections. This change includes those plugin settings in TOML and JSON output, using the same daemon-reported app-root and install-root config files as the core system properties. Nested plugin values preserve the existing first-match-wins layering behavior.

Fixes #607

Testing

• Tested locally
• Added/updated tests
• Added/updated docs

Commands run locally:

• swift test --filter PluginPropertiesTests
• swift test --filter ContainerCommandsTests

[amarkdotdev]

Gentle ping on this one (open since June 11). It implements #607 — container system property list now includes [plugin.*] settings in both TOML and JSON output, sourced from the same daemon-reported app-root and install-root config files as the core system properties, with the existing first-match-wins layering preserved.

It's self-contained (a new PluginProperties loader + PluginPropertyValue model, wired into PropertyList) and covered by tests for rendering, all TOML value types including nested tables, and precedence/override behavior (swift test --filter PluginPropertiesTests passes locally). The container project - PR build workflow is in the "action required" state pending a maintainer's approval to run. Could a maintainer approve the run and take a look? Happy to adjust anything. Fixes #607.