Function classify_test_migration 

pub fn classify_test_migration(
    engine: &Engine,
    index_store: &AsgIndexStore<'_>,
    candidate_qnames: &[String],
    query: &str,
) -> Recipe

First concrete recipe: classify the test-tier symbols matching a query by their migration story. Walks test files in scope, reads the ledger for each symbol, and picks an ActionKind per the role tags

• Mapping entries already in the ledger.

Decision tree (first match wins, per symbol):

1. Mapping entry → KeepAsCovered
2. Constraint/Decision with role=stale-api → Delete
3. Ownership/Concept with role=diagnostic-test → Gate
4. Ownership/Concept with role=fast-test + command → Run
5. Default → Review