**Phase:** 3 — Growth & Scale (Cost Optimization) Control SerpAPI spend per run: - [ ] Implement a search budget per run (e.g., max 20 API calls/day total across all subscribers) - [ ] Add adaptive query stopping — stop low-yield queries early based on a jobs-per-call threshold - [ ] Prioritize high-yield queries based on historical data - [ ] Log budget usage and remaining quota per run