Static HTML collection pages return wrong results (all redirect to same 9 products).
Switch to /collections/{handle}/products.json?limit=250&page=N API which is:
- Reliable JSON (no HTML parsing)
- Correct per-collection product lists
- Clean pagination (stop at < limit results)
- Covers 11 key transceiver collections (1G, 10G, 25G, 40G, 100G, 400G)