Resolved 22 compilation errors:
- Fixed lib.rs re-exports to use correct submodule paths
- Added missing submodule declarations to module files
- Created stub files for referenced submodules
- Fixed main.rs imports to use lib.rs re-exports
Project now compiles successfully with only 2 expected warnings:
- dead_code warning for jobs field in JobManager
- unused_variable warning for job_manager in main
Both warnings are expected for scaffolding phase.
