A PluginCatalog node over a local node-repo checkout lists nothing — BuildSource never selects the node-repo source, and the content has no format field #3384

Split out of #3359 (its fix option 3), where it was found and measured — it is its own defect and reaches every checkout-served source, not only the self-registry mode.

What happens

A PluginCatalog node created over a local node-repo checkout (sourceRepoPath: /plugin-repos/Education, the format memex-local mounts and NodeRepoPackageSource reads) creates fine, its Catalog area activates, and it renders "No installable packages found."

Why

CatalogLayoutAreas.BuildSource builds the area's source with

PackageSources.FromRepo(host.Hub, sourceRepoPath, sourceSubdir, Logger(host));

and never passes nodeRepo: true, so a LOCAL path falls through to GitPackageSource — the package.json format — which lists nothing for a node-repo tree. The factory's own comment names the outcome ("before this, a local path silently fell through to the package.json source below and listed nothing"). PluginCatalogContent carries only SourceRepoPath / SourceRef / SourceSubdir / Description — no format field — so a catalog node cannot select the node-repo source even deliberately.

Consequence

The documented human fallback for a stale install — "a human opening the catalog page … offers the same Update" — is unreachable for every checkout-served source. On a self-registry memex-local there is no catalog page at all out of the box (it seeds no PluginCatalog node), and creating one by hand does not help until this is fixed. #3359's fix (the mounted checkouts reconcile on every boot) removes the need for the fallback in that mode; this issue is what stands between an operator and the catalog page over any local checkout.

Fix shape

Either a Format member on PluginCatalogContent (node-repo default, package-json opt-in — the same knob PluginCatalog:Sources:N:Format already has), or detect the node-repo shape (a depth-2 <Folder>/index.json with a root nodeType — the predicate memex-local's is_node_repo and NodeRepoPackageSource already share) in BuildSource. Then memex-local can seed one PluginCatalog node per mounted repo so the page exists on a fresh install.

Measured on 2026-09-05 by the #3359 investigation (two catalog nodes over /plugin-repos/Education and /plugin-repos/Plugins, both empty).