Evaluate alternative job search APIs

**Phase:** 3 — Growth & Scale (Cost Optimization)

SerpAPI is expensive at scale (100 searches/month free, \$50/month for 5000). Evaluate alternatives:

- [ ] Google Custom Search API (free tier: 100 queries/day)
- [ ] Bing Jobs API
- [ ] Direct scraping as a fallback (with rate limiting)
- [ ] JSearch API (RapidAPI)

Compare: cost per query, result quality, rate limits, European market coverage.