Function resolve_target 

pub fn resolve_target(
    source: &impl ObjectSource,
    descriptor: ContentHash,
    scope: &CollaborationScope,
    state: StateId,
    target_id: ContentHash,
) -> Result<Option<ResolvedSourceTarget>, HeddleError>

Read one target and its file binding from a signed descriptor. Unlike closure, this walks only the two bounded trie routes and does not require unrelated targets to be retained locally. The caller supplies an admitted descriptor proof and independently authorizes any returned coordinates.