Fix non-git edge cases

[gtrevisan]

• make the log header more resilient to non-git runs
• avoid importing the tests module which is unavailable for non-git installs
• log critical error if no shots or no processors

[gtrevisan]

I tested that I could run the simple example with a non-git installation by creating a small PEP-723 script:

#!/usr/bin/env python3
# /// script
# requires-python = ">=3.11,<4.0"
# dependencies = ["disruption-py"]
# [tool.uv.sources]
# disruption-py = { git = "https://github.com/MIT-PSFC/disruption-py/", branch = "fix-non-git" }
# ///
from disruption_py.workflow import cli
cli()

and then running it with on-the-fly-venv creation with uv:

uv run test.py

indeed, if one uses the branch dev, instead, then the test fails with:

ModuleNotFoundError: No module named 'tests'