StigAnalyzerExecutionCoordinator

Limits concurrent native analyzer processes across activity projects in one Gradle build.

Each P6 activity task already executes its run-plan entries serially. Associating every active P6 task with this shared service therefore makes Parameters.maxParallelAnalyzerExecutions a strict build-wide upper bound on native analyzer processes. The permit currently covers the complete P6 task; the durable native-execution task will own it after that lifecycle is split from Kotlin validation.