Cut from #142 scope (planner step 7). az.bfmi (warn < 0.3) and max-treedepth saturation are genuinely VAR-relevant; treedepth needs a backend name map (reached_max_treedepth pymc vs maxdepth_reached nutpie). ~15 lines + tests. Files: src/impulso/diagnostics.py.
Cut from #142 scope (planner step 7).
az.bfmi(warn < 0.3) and max-treedepth saturation are genuinely VAR-relevant; treedepth needs a backend name map (reached_max_treedepthpymc vsmaxdepth_reachednutpie). ~15 lines + tests. Files:src/impulso/diagnostics.py.