- injector: for currency_per_unit_rate, rate_anchor_token is now mandatory. Absent or invalid → immediate return ().
No call to _locate_rate_verb for these anchors.
- tests: _rate_anchor helper now passes rate_anchor_token.
- Added hard confuser test for 'Alexa ... for one cup.' — live registry + inject_from_match must emit ().
- Strengthened distracting-a ' per' test to unconditional: m not None, RATE_WITH_CURRENCY, len==1, matched_verb=='per', roundtrip_admissible True.
- lookback updated for 11 files, include matcher.py, rate_anchor_token centrality, exact counts after this.