Most (all?) of our obs packages include meas_extensions_shapeHSM as an additional characterizeImage plugin. This overrides the default shape slots, and is generally considered a better shape measurement than the SdssShape algorithm.

Given that we generally expect that shapeHSM has been run and is the slot_shape output, we need to add it to the default plugin list in characterizeImageConfig.setDefaults() to ensure it is always run. The most important two plugins for the are "ext_shapeHSM_HsmSourceMoments", "ext_shapeHSM_HsmPsfMoments": we should add at least those. I don't know if "ext_shapeHSM_HsmPsfMomentsDebiased" is also necessary or if it changes the HsmPsfMoments results at all.

This is the HSM config we have settled on for AP, which is what I think would be a "minimal" HSM shape config:

config.plugins.names |= ["ext_shapeHSM_HsmSourceMoments", "ext_shapeHSM_HsmPsfMoments"]

config.slots.shape = "ext_shapeHSM_HsmSourceMoments"

config.slots.psfShape = "ext_shapeHSM_HsmPsfMoments"

I don't believe we want to use the config/enable.py file in the hsm package, as it turns on more things. We may want to remove that config file entirely so as not to confuse people, or create a few different minimal.py/maximal.py config files in hsm/config/ that can be imported.