Resolve the content-addressed identity of one resource without reading it.
This is what a host's own OfflineRegionResourceMatcher calls: the host
parses its request URL into a tile key, asset key, or document name, asks for
the identity, and hands it to the existing storage-backed fetch handler. The
region is still verified, scoped, and expiry-checked here, so a matcher can
never produce an identity for a region the caller may not read.
Resolve the content-addressed identity of one resource without reading it.
This is what a host's own OfflineRegionResourceMatcher calls: the host parses its request URL into a tile key, asset key, or document name, asks for the identity, and hands it to the existing storage-backed fetch handler. The region is still verified, scoped, and expiry-checked here, so a matcher can never produce an identity for a region the caller may not read.