Lib.rs

Central, language-agnostic complexity pass. Given a structural graph whose file nodes carry their absolute path as id, this reads each file, picks a rust-code-analysis parser by extension, and writes the metrics into the node's attrs as flat keys. It is the single place that knows rust-code-analysis; plugins emit structure only.

The metric attribute dictionary it can produce is exposed via metric_specs so the orchestrator can declare it in the snapshot.