Without it a Windows checkout (core.autocrlf=true) rewrites the frozen CSV
snapshot to CRLF and test_archived_cli_csv_reproduces_frozen_bytes fails on
a byte-exact hash. The repo already stores LF.
Adds qa/test_branch_paths.py pinning the main path and one inverted path per
decision for validate_aa_snapshot, validate_availability_snapshot,
validate_native_tariff_overrides, model_router._staleness and
_native_cost_and_headroom, then splits each into small helpers. Messages,
check order and results are unchanged.
evandro