Add pkg/process for spawning, monitoring, and orchestrating external
processes with Core ACTION integration:
- Service with framework.ServiceRuntime integration
- ACTION messages: ProcessStarted, ProcessOutput, ProcessExited
- RingBuffer for output capture
- Runner for orchestration (RunAll, RunSequential, RunParallel)
- Dependency graph support for QA pipelines
- Global convenience functions following i18n patterns
Also add docs/pkg/PACKAGE_STANDARDS.md defining how to create Core
packages, using pkg/i18n as the reference implementation.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
