Refactor _build_cli_args to table-driven CLI flag mapping

[dustinblack]

Summary

_build_cli_args in rusty_comms_plugin.py uses a long chain of explicit if statements to map TestRunConfig fields to CLI flags. This works but becomes harder to maintain as new flags are added — each new field requires a new conditional block with its own formatting logic.

Suggestion

Replace the if-chain with a table-driven approach — e.g. a list of (field_name, flag, transform) tuples iterated in a loop:

FLAG_MAP = [
    ("message_size", "-s", str),
    ("msg_count", "-i", str),
    ("duration", "-d", None),
    ("concurrency", "-c", str),
    ("buffer_size", "--buffer-size", str),
    ...
]

for field, flag, transform in FLAG_MAP:
    value = getattr(params, field, None)
    if value is not None:
        args.extend([flag, transform(value) if transform else value])

Boolean flags and special cases (like percentiles with repeated --percentiles args, or mechanisms which uses positional args) would need separate handling, but the bulk of the simple value flags could collapse into the loop.

Benefits

• Adding a new CLI flag becomes a one-line table entry instead of a new if-block
• Reduces risk of inconsistencies in flag formatting
• Easier to audit the full set of supported flags at a glance

Notes

Not urgent — the current implementation is correct and readable. This is a maintainability improvement for when the next batch of flags is added.