test_spacecraftHubOnlyFastPath

Unit tests for the automatic hub-only spacecraft dynamics fast path.

When no state effectors are attached and point \(B\) is colocated with the hub center of mass, Spacecraft can bypass the general Backsubstitution matrix assembly and ask HubEffector to compute direct rigid-body derivatives. This test validates the resulting translational and rotational dynamics against a simple analytic case.

test_spacecraftHubOnlyFastPath.test_spacecraftHubOnlyFastPath_matchesAnalyticForceTorque()

Hub-only fast path must reproduce direct rigid-body force/torque motion.