Sort providers by cost, latency, or throughput on AI Gateway

AI Gateway now allows sorting providers by cost, latency, or throughput to optimize request routing based on specific needs.

• •Three sorting options available: 'cost' for lowest price, 'ttft' for lowest latency, 'tps' for highest throughput
• •Sorting is computed at request time, automatically reflecting provider changes, price updates, and latency shifts without code changes
• •Compatible with other gateway routing options like Zero Data Retention (ZDR) for combined filtering and sorting
• •Providers are tried in sort order with fallback to next provider only when current one is unavailable
• •Every response includes routing metadata showing providers considered, metric values, execution order, and deprioritized providers