Norg transclusion attribute inheritance across files

Clarify the documented behavior for norg block transclusion when a block with properties is embedded in a different file.

The norg spec defines blocks with IDs, properties and transclusion syntax. The unresolved decision is whether a transcluded block preserves its original attributes, inherits context from the parent file, or merges both, and how updates to the source block are reflected in the transclusion target.

Assumptions are based on the current norg spec as implemented in tools that use norg. Practical verification would require inspecting serialized norg output after transclusion.

Does norg transclusion render the source block's properties unchanged in the target context? Which attribute source takes precedence if the same property exists in both source and target? When is a transcluded block considered an independent copy versus a live reference?