codemap 0.0.16 — where a change lands in a scenario, and what found each edge

Schema 0.13, unchanged for the fifth release, and no graph bytes move: the same tree
built by 0.0.15 and by 0.0.16 from PyPI is byte-identical in nodes and edges, only
provenance differs. Consumers bump the pin and re-extract nothing.

- R1-C40: `report impact` names the flows a change lands on and the step it lands at
  (one reverse BFS; agreed with the forward walk on 1324 + 252 measured pairs, 0
  mismatches). Reached, not broken — the graph knows the symbol is on the path.
- R1-C39: the `extras.resolution` vocabulary is closed and graded (exact / inferred /
  heuristic), `callers`/`callees` take min_confidence, `stats` reports the mix. The
  grade is derived, not stored — which is why the artifact does not move.

Both items came from our own reading of a neighbouring tool, not from a filed issue,
and both needed less than the backlog entry that proposed them.