algebra/rotor.py and persona/motor.py were calling normalize_to_versor()
which is the gate-only injection primitive. Both are construction-time
sites (building rotors and motors from raw arrays), so the correct call
is unitize_versor().
Also tightens TestINV02 to scan for normalize_to_versor violations only —
unitize_versor has its own legitimate call sites and is not under the
same single-site restriction. Adds a new TestINV02b that verifies
unitize_versor is NOT called inside propagation, generation, or vault
recall paths.
Fixes: INV-02 architectural invariant test failure.