Add ss= keyword argument to MIMOStateSpace.__init__

Jeff

I ran into this while trying to run https://git.ligo.org/b111/sflu-optomechanics/-/blob/main/fromgwinc/intsqz/test_CCwIntSqz.py?ref_type=heads, and I get the same error on wield-control dev and main.

Claude

SScompute.py passes a state-space object via ss=E keyword, but MIMOStateSpace.init only accepted positional args for this. Add ss= as an explicit keyword that feeds into the existing positional dispatch logic, consistent with the A=, B=, C=, D=, E= keywords already on dev.

Co-Authored-By: Claude Opus 4.6 noreply@anthropic.com