Evidence layout
Current formal run: formal_1.7.0/.
Current integrated release run: release_1.7.0/.
Current development failures/corrections: development_1.7.0/.
lean/ and the earlier versioned directories retain historical runs. They
must not be reported as fresh verification of modified sources. The new run
uses pinned cached imports and Lean's own kernel; it is not an independent
validator or a full rebuild of Mathlib. Source hashes bind each record to the
files actually checked.