feat: add pipeline v2 csv ingest contract

feat: add pipeline v2 row adapters

feat: add pipeline v2 aggregate tables

feat: add pipeline v2 entrypoint

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

* **New Features**
  * Pipeline v2: new ingest flow with 5‑minute bucketing, MAAD integration, and v2 aggregated outputs; UI/API now expose per‑IP‑family metrics.

* **UI/UX Changes**
  * NetFlow dashboard: optional IP‑family selector and per‑family breakdowns; file page hides singularities and file summary shows richer, safer metadata formatting.

* **Documentation**
  * Added Pipeline v2 spec and operational docs covering config and mapping contract.

* **Tests**
  * Comprehensive test coverage for CSV mapping, normalization, nfdump, MAAD, aggregation, persistence, and schema validation.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->