Count rows of a target entity right now.
the target entity (model's training-unit entity)
OptionalextraFilter: stringoptional filter narrowing the population (mirrors the pipeline scope)
OptionalcontextUser: UserInforequest user — required server-side for isolation/audit
Optionalprovider: IMetadataProvideroptional provider for multi-provider correctness
Counter seam — returns the CURRENT row count of a target entity (optionally filtered), so the data-volume trigger can compare today's count against the model's
TrainingRowCount. Wraps aRunViewcount in production; tests inject a fake returning canned counts.