Join: merge A3 (wip/registry-a3)

Conflicts, both sides kept: artifact-store-tools' invokes (the assigner's
and indexer's read tools, followed through views, beside the registry
seats' hold, release and remove), its main (the views reader and the
seat asker), its manifest row; gitea's invokes (the indexer's read tool,
the hand act and the builder's versions) and its consumes of the
indexer's views. gitea's account test takes the packages account's
names; repoCheckFacts, removed on main, is not imported. No catalogue
module reads the indexer's state.

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

.gitignore

@@ -36,6 +36,7 @@ modules/mesh-build-image/cmd/mesh-build-image/mesh-build-image
 
 # binaries a local go build leaves in a module root
 /checks/paths/paths
+/checks/environment/environment
 /modules/mesh-build-go/mesh-build-go
 /modules/mesh-delivery-gate/mesh-delivery-gate
 modules/mesh-config/cmd/mesh-config/mesh-config