Build Enrichment Batch Removed

DEPRECATED — removed in favor of POST /api/v1/pipeline/trigger.

The old implementation built a Tracerfy batch and ran the enrichment pipeline (skip_trace → gapfill → validate → score → reload) as a local background thread inside the API container. That container is not provisioned to run paid enrichment stages, so the path failed in production (TX job 5ac78544: skip_trace "exit code 1" after ~90s).

The Browse selection bar and Lead Detail "Send to Pipeline…" actions now call POST /api/v1/pipeline/trigger (PR #536), which runs stages as isolated ECS tasks with a Run Manifest for per-entity COGS attribution. This endpoint returns 410 Gone; there are no remaining callers in the frontend or the agent layer.