feat(FN-4772): complete Step 1 — export HybridExecutor

Fusion-Task-Id: FN-4772
Fusion-Task-Lineage: d296e96a-fe44-4896-928a-fa44da62b41a

packages/engine/src/__tests__/hybrid-executor.test.ts

@@ -1,6 +1,7 @@
 import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
 import type { CentralCore, RegisteredProject } from "@fusion/core";
 import { HybridExecutor } from "../hybrid-executor.js";
+import * as engine from "../index.js";
 import type { ProjectRuntimeConfig } from "../project-runtime.js";
 
 // Mock the ProjectManager
@@ -109,6 +110,10 @@ vi.mock("../node-health-monitor.js", () => ({
 }));
 
 describe("HybridExecutor", () => {
+  it("is exported from engine index", () => {
+    expect(engine.HybridExecutor).toBe(HybridExecutor);
+  });
+
   let executor: HybridExecutor;
   let mockCentralCore: CentralCore;
   const mockProject: RegisteredProject = {

packages/engine/src/index.ts

@@ -252,6 +252,11 @@ export { ProjectManager } from "./project-manager.js";
 export { ProjectEngine, type ProjectEngineOptions } from "./project-engine.js";
 export { ProjectEngineManager, type EngineManagerOptions } from "./project-engine-manager.js";
 export { NodeHealthMonitor } from "./node-health-monitor.js";
+export {
+  HybridExecutor,
+  type HybridExecutorOptions,
+  type HybridExecutorEvents,
+} from "./hybrid-executor.js";
 export { applyUnavailableNodePolicy, type PolicyDecision } from "./node-routing-policy.js";
 export { PeerExchangeService, type PeerExchangeServiceOptions, type SyncResult } from "./peer-exchange-service.js";
 export {