Draft v5.0.2

Fixed

• The README described the graph tools as they were before 5.0. Impact
  analysis listed doc/config buckets and "tests/docs/configs" (it reports
  dependents through calls and imports, split code/test), the call graph
  claimed confidence signals it does not emit, and hotspot ranking and
  indexing understated what they do. It now describes the fail-loud callers
  status, dependents-by-hop impact, fan-in-plus-complexity hotspots,
  refresh-before-query indexing, and the pinned-hash engine install.