TestCatalogValid fails: chimerax/paraview catalog images are private ECR, not public

[scttfrdmn]

make check / go test ./cmd/... fails on main (confirmed via git stash, unrelated to any in-flight change):

catalog invalid: chimerax: image "942542972736.dkr.ecr.us-east-1.amazonaws.com/chimerax" is private — the shipped catalog must be public; put private images in a local overlay (#392)
catalog invalid: paraview: image "942542972736.dkr.ecr.us-east-1.amazonaws.com/paraview" is private — the shipped catalog must be public; put private images in a local overlay (#392)

Per #392's rule, the shipped catalog must reference only public images; private images belong in a local overlay. chimerax and paraview currently point at a private ECR repo (942542972736...) in the shipped catalog, which TestCatalogValid correctly rejects.

Found while running make check for an unrelated PR (#353's headless container primitive) — not caused by it, just discovered it's currently red on main.