feat: add runner failover rules and cache affinity

apps/api/internal/runner/recording.go

@@ -139,6 +139,19 @@ func attemptMetrics(candidate store.RuntimeModelCandidate, attemptNo int, simula
 			"queued": candidate.LoadMetrics.QueuedCount,
 		}
 	}
+	if candidate.CacheAffinity.Key != "" {
+		metrics["cacheAffinityKey"] = candidate.CacheAffinity.Key
+		metrics["cacheAdjustedPriority"] = candidate.CacheAffinity.AdjustedPriority
+		metrics["cacheAffinitySamples"] = candidate.CacheAffinity.RequestCount
+		metrics["cacheAffinityScore"] = candidate.CacheAffinity.Score
+		metrics["cacheAffinityConfidence"] = candidate.CacheAffinity.Confidence
+		metrics["cacheAffinityHitRatio"] = candidate.CacheAffinity.EMAHitRatio
+		metrics["cacheAffinityEMAHitRatio"] = candidate.CacheAffinity.EMAHitRatio
+		metrics["cacheAffinityLastHitRatio"] = candidate.CacheAffinity.LastHitRatio
+		metrics["cacheAffinityCachedInputTokens"] = candidate.CacheAffinity.CachedInputTokens
+		metrics["cacheAffinityBoost"] = candidate.CacheAffinity.Boost
+		metrics["cacheAffinityApplied"] = candidate.CacheAffinity.Applied
+	}
 	if attemptNo > 0 {
 		metrics["attempt"] = attemptNo
 	}
@@ -151,9 +164,10 @@ func usageToMap(usage clients.Usage) map[string]any {
 		out["inputTokens"] = usage.InputTokens
 		out["promptTokens"] = usage.InputTokens
 	}
-	if usage.CachedInputTokens > 0 {
+	if usage.CachedInputTokensKnown || usage.CachedInputTokens > 0 {
 		out["cachedInputTokens"] = usage.CachedInputTokens
 		out["cachedPromptTokens"] = usage.CachedInputTokens
+		out["cachedInputTokensKnown"] = usage.CachedInputTokensKnown
 	}
 	if usage.OutputTokens > 0 {
 		out["outputTokens"] = usage.OutputTokens