perf: reuse reactor projects in remote resources

[efegokdemir]

Summary

Reuse Maven reactor projects when resolving the project list exposed to remote-resource templates, avoiding a redundant model build for each matching reactor dependency.

Changes

• Match dependency artifacts to reactor projects by groupId, artifactId, and version/baseVersion.
• Build project models only for dependencies that are not already present in the reactor.
• Add regression coverage for timestamped snapshot matching and non-matching external artifacts.

Testing

• mvn -DskipITs -Dspotless.skip=true -Dtest=RemoteResourcesMojoTest test — passed (12 tests)
• mvn -DskipITs -Dspotless.skip=true verify — passed
• git diff --check — passed
• mvn -Dspotless.skip=true -Prun-its verify — core integration tests passed, but the build finished failed because the local JDK 27 is incompatible with the repository's Groovy post-build scripts (Unsupported class file major version 71).

Refs #270