fix(qa): tolerate tool version drift in snapshot comparison

fix(qa): tolerate tool version drift in snapshot comparison

Compare snapshots with basedpyrightVersion normalized out: a tool upgrade that changes no diagnostics no longer fails the check. The recorded version stays in snapshots and --write output as provenance, is still validated nonempty on both sides, still appears in the failure diff, and both versions are reported in the success message. Diagnostics, file inventory and schema stay byte-exact, so changed output still fails closed. Covers scripts/test_check_basedpyright.py (stdlib unittest): version-only drift matches, diagnostic change mismatches, empty version and missing key rejected.