[pyoutline/rqd] `pycuerun` not installable via pip, CLI bugs, and sandbox cannot execute frames

[ramonfigueiredo]

Describe the bug
Several issues prevent the OpenCue sandbox from working end-to-end when submitting jobs via pyoutline:

1. pycuerun is not on PATH after pip install: pyoutline/pyproject.toml has no [project.scripts] entry point, so pip install pyoutline/ does not create a pycuerun command. Users must manually symlink or add the bin/ directory to PATH.

2. Missing --priority option in CuerunOptionParser: options_to_args() references options.priority, but the parser never defines a --priority option, causing:
   AttributeError: 'Values' object has no attribute 'priority'.

3. Empty --repos flag consumes the next CLI argument: When outline.versions.get_repos() returns an empty string, build_command() emits --repos with no value, which causes it to consume the next flag (e.g. --debug) as its argument.

4. use_pycuerun=False crashes for layers without a command arg: serialize_simple() calls " ".join(layer.get_arg("command")), which raises TypeError when command is None (e.g. custom Layer subclasses).

5. RQD Docker container cannot execute frames: The rqd container does not have pyoutline or pycue installed, so the wrapper script and pycuerun are unavailable. The default opencue_wrap_frame requires /bin/tcsh, which is not present in the container. There is also no python symlink (only python3.9), so #!/usr/bin/env python shebangs fail.

To Reproduce

Bug 1:

1. pip install pyoutline/
2. Run pycuerun my_job.outline
3. Result: command not found: pycuerun

Bug 2:

1. Run pycuerun --priority 100 my_job.outline
2. Result: AttributeError: 'Values' object has no attribute 'priority'

Bug 3:

1. Run pycuerun in an environment where OL_REPOS is unset and no repos are configured
2. The --repos flag with an empty value consumes the next argument

Bug 4:

1. Create a custom Layer subclass and launch with use_pycuerun=False
2. Result: TypeError: can only join an iterable

Bug 5:

1. Run docker compose up with the sandbox
2. Submit a job via pycuerun
3. Frames fail with errors such as:
   /bin/tcsh: bad interpreter: No such file or directory
   or
   env: 'python': No such file or directory

Expected behavior

• pip install pyoutline/ should make pycuerun available on PATH
• --priority should be a valid CLI option
• Empty --repos should not be emitted
• use_pycuerun=False should give a clear error for layers without a command instead of a TypeError
• The rqd Docker container should be able to execute frames out of the box

Version Number

• https://github.com/AcademySoftwareFoundation/OpenCue/releases/tag/v1.13.8