fix(api): require api server callbacks

tests/unit/api-server-callbacks.test.ts

@@ -0,0 +1,30 @@
+import { describe, expect, it } from "vitest";
+import { createApiServer, type ApiServerEventCallbacks } from "../../src/main/api-server";
+import type { AppDatabase } from "../../src/main/database";
+import { createTestApiServerCallbacks } from "../support/api-server-callbacks";
+
+describe("api server callback contract", () => {
+  it("fails during construction when the callback object is missing", () => {
+    expect(() => {
+      createApiServer({} as AppDatabase, undefined as unknown as ApiServerEventCallbacks);
+    }).toThrow("Missing AgentApiServer callbacks.");
+  });
+
+  it("fails during construction when a required callback is missing", () => {
+    const callbacks: Partial<ApiServerEventCallbacks> = createTestApiServerCallbacks();
+    delete callbacks.onTaskCreated;
+
+    expect(() => {
+      createApiServer({} as AppDatabase, callbacks as ApiServerEventCallbacks);
+    }).toThrow("Missing AgentApiServer callback: onTaskCreated");
+  });
+
+  it("constructs the server when every callback is explicit", () => {
+    const callbacks = createTestApiServerCallbacks();
+    const server = createApiServer({} as AppDatabase, callbacks);
+
+    expect(server.callbacks.onTaskCreated).toBe(callbacks.onTaskCreated);
+    expect(server.onDomainChanged).toBe(callbacks.onDomainChanged);
+    expect(server.onWakeAgent).toBe(callbacks.onWakeAgent);
+  });
+});