House-style ADR/blueprint parsing and roteiro check drift detection.
An ADR becomes an adr node with adr_section children; its
[[path#Symbol]] wiki-links and @rto:<id> source annotations become
authored edges into the derived code graph. [check::run] validates those
links against the graph and fails on drift (a link to a missing symbol, or a
@rto: annotation to an unknown or superseded ADR).