fix: restore V3 HTTP observability

Project one typed HttpExecutionObservation per logical V3 execution through a
closed composition-root projector: only registered diagnostic context keys and
bucketed values reach the sinks, and terminal non-abort failures now emit
exactly one api.request.failed telemetry event. Caller cancellation and scope
fencing record a diagnostic but never a failure event.

routeId becomes a required input at the installed operation-executor boundary
so the feature gateway's low-cardinality route identity survives to the sink.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/integration/http-scenario-catalog.test.ts

@@ -4,7 +4,10 @@ import path from "node:path";
 import { afterAll, beforeAll, describe, expect, it } from "vitest";
 
 import { readBoundedBytes } from "../../src/adapters/http/bounded-body-reader.ts";
-import { createContractHttpExecutor } from "../../src/adapters/http/http-execution-v3.ts";
+import {
+  createContractHttpExecutor,
+  type HttpExecutionObservation,
+} from "../../src/adapters/http/http-execution-v3.ts";
 import {
   type InstalledHttpContract,
 } from "../../src/contracts/external-contract-runtime.ts";
@@ -30,6 +33,13 @@ import {
   type HttpScenarioOperationId,
 } from "../mocks/scenarios/catalog.ts";
 
+/** The reference gateway owns these low-cardinality route identities. */
+function routeIdFor(operationId: HttpScenarioOperationId): string {
+  return operationId === "GET_REFERENCE_RESOURCE"
+    ? "REFERENCE_RESOURCE_DETAIL"
+    : "REFERENCE_RESOURCE_LIST";
+}
+
 const RECEIPT_PATH = path.resolve(
   "artifacts/tests/http-scenario-executions.json",
 );
@@ -191,11 +201,7 @@ async function executeScenario(
 ): Promise<HttpScenarioAssertionGroups> {
   const physicalAttempts: AttemptTrace[] = [];
   const sleeps: RetryReason[] = [];
-  const observations: Array<Readonly<{
-    outcome: string;
-    attempts: number;
-    certainty: string;
-  }>> = [];
+  const observations: HttpExecutionObservation[] = [];
   const caller = new AbortController();
   const scopeLifetime = new AbortController();
   let scopeCurrent = true;
@@ -265,6 +271,7 @@ async function executeScenario(
 
   try {
     const execution = executor.execute(operation, inputFor(entry.operationId), {
+      routeId: routeIdFor(entry.operationId),
       scope,
       signal: caller.signal,
       ...(entry.operationId === "CREATE_REFERENCE_RESOURCE"
@@ -296,7 +303,7 @@ async function executeScenario(
     const observation = observations[0]!;
     const observedSignal = scopeLifetime.signal.aborted ? "ABORTED" : "ACTIVE";
     const cancellationOwner =
-      observation.certainty === "TIMEOUT"
+      observation.terminalReason === "TIMEOUT"
         ? "DEADLINE"
         : caller.signal.aborted
           ? "CALLER"
@@ -314,13 +321,13 @@ async function executeScenario(
       }),
       effect: Object.freeze({
         outcome: String(outcome.effect),
-        observer: observation.certainty,
+        observer: observation.terminalReason,
       }),
       retry: Object.freeze({ count: sleeps.length, reasons: Object.freeze(sleeps) }),
       fetch: Object.freeze({
         count: physicalAttempts.length,
-        observerAttempts: observation.attempts,
-        agrees: physicalAttempts.length === observation.attempts,
+        observerAttempts: observation.attemptCount,
+        agrees: physicalAttempts.length === observation.attemptCount,
       }),
       media: Object.freeze({
         attempts: Object.freeze(physicalAttempts.map((attempt) => attempt.media)),