A seal index that cannot be read holds instead of opening

A GitSynced Space advances only to a commit sealed for the framework identity its instance runs. The gate decides that from the list of publications sealed for this identity, and answers "not my business, carry on" when the list is empty — which is right for an instance that runs no publication of the repository at all.

Until now that same empty list was also what a failed read produced. A published root that could not be enumerated therefore did not stop anything: it let every repository advance, which is the exact opposite of the rule, and the only trace was one warning in a log nothing checks.

The reading now says which it is, and a failure holds every source rather than opening them:

the publication index for this instance's framework identity sd608997… could not be READ — that is an absence of measurement, not an empty index, so every source is held rather than advanced. 'Cannot tell' is never 'clear to proceed'

Two states that look alike are kept apart deliberately. Nothing at the identity's path is ordinary — a framework line nobody has published for yet — and still reads as a clean empty, because treating it as a failure would freeze every source on every new platform line. Something that is not an enumerable directory at exactly that path is a failure, because that is what a half-finished layout migration looks like from this reader.

Full detail: Publication Seal Starvation.