for testability
- Add `ManagedChild` trait abstracting process lifecycle (real
`TokioChild` + `MockChild` for tests)
- Use Unix process groups (`process_group(0)` + `libc::kill(-pgid,
SIGKILL)`) for tree-wide termination
- Remove cgroup-related code (`CgroupManager`, `ResourceUsage`,
`cgroup_path` field)
- Update imports across test files to use `workshop-engine` crate
directly
Add new `build_status` types module for tracking pipeline stage
execution
status across prebake, bake, and finalize phases. Introduce
`NotificationCore`
dispatcher that processes notification methods by priority groups with
fallback
on failure. Status files written to `/tmp/.hbwstatus` in JSON lines
format.
Catty Steve