Add Program to the process package as a lightweight tool-finder and runner.
Find() resolves a binary via exec.LookPath (wrapping ErrProgramNotFound),
Run() and RunDir() execute the binary and return trimmed combined output.
Includes 7 tests covering happy paths, error paths, and the errors.Is contract.
Co-Authored-By: Virgil <virgil@lethean.io>
Five Lit custom elements following the go-scm UI pattern:
- <core-process-panel> tabbed container (Daemons/Processes/Pipelines)
- <core-process-daemons> daemon registry with health checks and stop
- <core-process-list> managed processes with status badges
- <core-process-output> live stdout/stderr WS stream viewer
- <core-process-runner> pipeline execution results display
Also adds provider.Renderable interface to ProcessProvider with
Element() returning core-process-panel tag, extends WS channels
with process-level events, and embeds the built UI bundle via
go:embed.
Co-Authored-By: Virgil <virgil@lethean.io>
