feat(analytics): add latency histogram buckets to analytics summary

apps/api/src/lib/storage/serialization.ts

@@ -1,6 +1,7 @@
 import type {
   AnalyticsSummary,
   ExecutionFallbackReason,
+  LatencyBucket,
   PaymentAttempt,
   QueryMode,
   UsageEvent
@@ -14,6 +15,18 @@ function emptySpendByCategory(): Record<QueryMode, number> {
   return { search: 0, news: 0, scrape: 0 };
 }
 
+function emptyLatencyBuckets(): Record<LatencyBucket, number> {
+  return { "<1s": 0, "1-3s": 0, "3-10s": 0, ">10s": 0, unknown: 0 };
+}
+
+function classifyLatency(latencyMs: number): LatencyBucket {
+  if (latencyMs <= 0) return "unknown";
+  if (latencyMs < 1000) return "<1s";
+  if (latencyMs < 3000) return "1-3s";
+  if (latencyMs < 10000) return "3-10s";
+  return ">10s";
+}
+
 function emptyExecutionSummary(): NonNullable<AnalyticsSummary["executionSummary"]> {
   return {
     totalExecutions: 0,

apps/web/src/types.ts

@@ -1,4 +1,4 @@
-import type { ProviderDefinition, QueryMode, QueryResult } from "@query402/shared";
+import type { LatencyBucket, ProviderDefinition, QueryMode, QueryResult } from "@query402/shared";
 
 export interface PaymentProofLinks {
   transaction: string;

packages/shared/src/types.ts

@@ -11,6 +11,8 @@ export type ExecutionFallbackReason =
 export type CircuitBreakerState = "closed" | "half-open" | "open";
 export type PaymentSource = "sponsored" | "wallet" | "demo";
 
+export type LatencyBucket = "<1s" | "1-3s" | "3-10s" | ">10s" | "unknown";
+
 export interface ProviderExecutionMetadata {
   providerId: string;
   source: SourceType;