diff --git a/src/agents/subagent-registry.context-engine.test.ts b/src/agents/subagent-registry.context-engine.test.ts
deleted file mode 100644
index 5cdfe3ddc83..00000000000
--- a/src/agents/subagent-registry.context-engine.test.ts
+++ /dev/null
@@ -1,122 +0,0 @@
-import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
-import type { SubagentRunRecord } from "./subagent-registry.types.js";
-
-const noop = () => {};
-
-const mocks = vi.hoisted(() => ({
-  loadConfig: vi.fn(() => ({})),
-  ensureRuntimePluginsLoaded: vi.fn(),
-  ensureContextEnginesInitialized: vi.fn(),
-  resolveContextEngine: vi.fn(),
-  onSubagentEnded: vi.fn(async () => {}),
-  onAgentEvent: vi.fn(() => noop),
-  persistSubagentRunsToDisk: vi.fn(),
-  restoreSubagentRunsFromDisk: vi.fn(() => 0),
-  getSubagentRunsSnapshotForRead: vi.fn((runs: Map<string, SubagentRunRecord>) => new Map(runs)),
-}));
-
-vi.mock("../config/config.js", async () => {
-  const actual = await vi.importActual<typeof import("../config/config.js")>("../config/config.js");
-  return {
-    ...actual,
-    loadConfig: mocks.loadConfig,
-  };
-});
-
-vi.mock("../context-engine/init.js", () => ({
-  ensureContextEnginesInitialized: mocks.ensureContextEnginesInitialized,
-}));
-
-vi.mock("../context-engine/registry.js", () => ({
-  resolveContextEngine: mocks.resolveContextEngine,
-}));
-
-vi.mock("../infra/agent-events.js", () => ({
-  onAgentEvent: mocks.onAgentEvent,
-}));
-
-vi.mock("./runtime-plugins.js", () => ({
-  ensureRuntimePluginsLoaded: mocks.ensureRuntimePluginsLoaded,
-}));
-
-vi.mock("./subagent-registry-state.js", () => ({
-  getSubagentRunsSnapshotForRead: mocks.getSubagentRunsSnapshotForRead,
-  persistSubagentRunsToDisk: mocks.persistSubagentRunsToDisk,
-  restoreSubagentRunsFromDisk: mocks.restoreSubagentRunsFromDisk,
-}));
-
-vi.mock("./subagent-announce-queue.js", () => ({
-  resetAnnounceQueuesForTests: vi.fn(),
-}));
-
-vi.mock("./timeout.js", () => ({
-  resolveAgentTimeoutMs: vi.fn(() => 1_000),
-}));
-
-describe("subagent-registry context-engine bootstrap", () => {
-  let mod: typeof import("./subagent-registry.js");
-
-  beforeAll(async () => {
-    mod = await import("./subagent-registry.js");
-  });
-
-  beforeEach(() => {
-    vi.clearAllMocks();
-    mocks.resolveContextEngine.mockResolvedValue({
-      onSubagentEnded: mocks.onSubagentEnded,
-    });
-    mod.__testing.setDepsForTest({
-      loadConfig: mocks.loadConfig,
-      ensureRuntimePluginsLoaded: mocks.ensureRuntimePluginsLoaded,
-      ensureContextEnginesInitialized: mocks.ensureContextEnginesInitialized,
-      resolveContextEngine: mocks.resolveContextEngine,
-      onAgentEvent: mocks.onAgentEvent,
-      persistSubagentRunsToDisk: mocks.persistSubagentRunsToDisk,
-      restoreSubagentRunsFromDisk: mocks.restoreSubagentRunsFromDisk,
-      getSubagentRunsSnapshotForRead: mocks.getSubagentRunsSnapshotForRead,
-    });
-    mod.resetSubagentRegistryForTests({ persist: false });
-  });
-
-  afterEach(() => {
-    mod.__testing.setDepsForTest();
-    mod.resetSubagentRegistryForTests({ persist: false });
-  });
-
-  it("reloads runtime plugins with the spawned workspace before released subagent end hooks", async () => {
-    mod.addSubagentRunForTests({
-      runId: "run-1",
-      childSessionKey: "agent:main:session:child",
-      controllerSessionKey: "agent:main:session:parent",
-      requesterSessionKey: "agent:main:session:parent",
-      requesterOrigin: undefined,
-      requesterDisplayKey: "parent",
-      task: "task",
-      cleanup: "keep",
-      expectsCompletionMessage: undefined,
-      spawnMode: "run",
-      workspaceDir: "/tmp/workspace",
-      createdAt: 1,
-      startedAt: 1,
-      sessionStartedAt: 1,
-      accumulatedRuntimeMs: 0,
-      cleanupHandled: false,
-    });
-
-    mod.releaseSubagentRun("run-1");
-
-    await vi.waitFor(() => {
-      expect(mocks.onSubagentEnded).toHaveBeenCalledWith({
-        childSessionKey: "agent:main:session:child",
-        reason: "released",
-        workspaceDir: "/tmp/workspace",
-      });
-    });
-    expect(mocks.ensureRuntimePluginsLoaded).toHaveBeenCalledWith({
-      config: {},
-      workspaceDir: "/tmp/workspace",
-      allowGatewaySubagentBinding: true,
-    });
-    expect(mocks.ensureContextEnginesInitialized).toHaveBeenCalledTimes(1);
-  });
-});
diff --git a/src/agents/subagent-registry.test.ts b/src/agents/subagent-registry.test.ts
index 3cb6ac856b9..0becee9fd4c 100644
--- a/src/agents/subagent-registry.test.ts
+++ b/src/agents/subagent-registry.test.ts
@@ -508,4 +508,44 @@ describe("subagent registry seam flow", () => {
       });
     });
   });
+
+  it("loads plugin and context-engine runtime before released end hooks", async () => {
+    mod.addSubagentRunForTests({
+      runId: "run-release-context-engine",
+      childSessionKey: "agent:main:session:child",
+      controllerSessionKey: "agent:main:session:parent",
+      requesterSessionKey: "agent:main:session:parent",
+      requesterOrigin: undefined,
+      requesterDisplayKey: "parent",
+      task: "task",
+      cleanup: "keep",
+      expectsCompletionMessage: undefined,
+      spawnMode: "run",
+      workspaceDir: "/tmp/workspace",
+      createdAt: 1,
+      startedAt: 1,
+      sessionStartedAt: 1,
+      accumulatedRuntimeMs: 0,
+      cleanupHandled: false,
+    });
+
+    mod.releaseSubagentRun("run-release-context-engine");
+
+    await vi.waitFor(() => {
+      expect(mocks.onSubagentEnded).toHaveBeenCalledWith({
+        childSessionKey: "agent:main:session:child",
+        reason: "released",
+        workspaceDir: "/tmp/workspace",
+      });
+    });
+    expect(mocks.ensureRuntimePluginsLoaded).toHaveBeenCalledWith({
+      config: {
+        agents: { defaults: { subagents: { archiveAfterMinutes: 0 } } },
+        session: { mainKey: "main", scope: "per-sender" },
+      },
+      workspaceDir: "/tmp/workspace",
+      allowGatewaySubagentBinding: true,
+    });
+    expect(mocks.ensureContextEnginesInitialized).toHaveBeenCalledTimes(1);
+  });
 });