- Rename cli/src/commands/exec/ → executor/ (4 files)
- Rename cli/src/commands/queue/ → submission/ (4 files)
- Create new submission/index.zig, delete queue/index.zig
The new names better reflect the purpose of these modules:
- 'executor' for local/remote execution logic
- 'submission' for job submission and queue management
This is a pure rename with no functional changes.
