Add Metro DI sample app (service-metro)

[Copilot]

New sample app demonstrating Metro dependency injection as an alternative to the existing Hilt-based service-hilt sample.

Changes

Version Catalog (gradle/libs.versions.toml)

• Added Metro 0.10.2 plugin and runtime dependency

New Module (samples/service-metro/)

• ServiceScope annotation for service-scoped dependencies
• AppGraph using @DependencyGraph(AppScope::class) for app-level DI
• ServiceGraph using @GraphExtension(ServiceScope::class) for service-level DI

Key Metro Patterns

@GraphExtension(ServiceScope::class)
@SingleIn(ServiceScope::class)
interface ServiceGraph {
    val serviceOverlay: ServiceOverlay

    @GraphExtension.Factory
    interface Factory {
        fun create(): ServiceGraph
    }
}

Graph creation in FloatingApplication:

val appGraph: AppGraph by lazy {
    createGraphFactory<AppGraph.Factory>().create(this)
}

Service obtains scoped dependencies via graph extension:

serviceGraph = FloatingApplication.instance.appGraph.serviceGraphFactory.create()

Verified with ./gradlew :samples:service-metro:assembleDebug.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• zacsweers.github.io
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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