diff --git a/src/agents/models-config.providers.auth-aliases.test.ts b/src/agents/models-config.providers.auth-aliases.test.ts
index ef2aa9a0c7c..a37eeacc93a 100644
--- a/src/agents/models-config.providers.auth-aliases.test.ts
+++ b/src/agents/models-config.providers.auth-aliases.test.ts
@@ -63,7 +63,7 @@ vi.mock("../plugins/manifest-registry.js", () => ({
 }));
 vi.mock("../plugins/manifest-registry-installed.js", () => ({
   loadPluginManifestRegistryForInstalledIndex: loadPluginManifestRegistry,
-  resolveInstalledManifestRegistryIndexFingerprint: () => "test-index",
+  resolveInstalledManifestRegistryIndexFingerprint: () => "test-installed-index",
 }));
 vi.mock("../plugins/plugin-registry.js", () => ({
   loadPluginRegistrySnapshot: () => ({ plugins: [] }),
diff --git a/src/agents/pi-embedded-runner/compact.hooks.test.ts b/src/agents/pi-embedded-runner/compact.hooks.test.ts
index ab8d647a7b1..45de0f9c399 100644
--- a/src/agents/pi-embedded-runner/compact.hooks.test.ts
+++ b/src/agents/pi-embedded-runner/compact.hooks.test.ts
@@ -1328,13 +1328,6 @@ describe("compactEmbeddedPiSession hooks (ownsCompaction engine)", () => {
         sessionFile: TEST_SESSION_FILE,
       },
     } as never);
-    rotateTranscriptAfterCompactionMock.mockResolvedValueOnce({
-      rotated: true,
-      sessionId: "wrapper-rotated-session",
-      sessionFile: "/tmp/wrapper-rotated-session.jsonl",
-      leafId: "wrapper-rotated-leaf",
-    });
-
     const result = await compactEmbeddedPiSession(
       wrappedCompactionArgs({
         config: {
diff --git a/src/agents/sessions-spawn-hooks.test.ts b/src/agents/sessions-spawn-hooks.test.ts
index e7c84265bfd..88d514de2ed 100644
--- a/src/agents/sessions-spawn-hooks.test.ts
+++ b/src/agents/sessions-spawn-hooks.test.ts
@@ -65,12 +65,12 @@ async function spawn(params?: {
   runTimeoutSeconds?: number;
   thread?: boolean;
   mode?: "run" | "session";
+  context?: "isolated" | "fork";
   agentSessionKey?: string;
   agentChannel?: string;
   agentAccountId?: string;
   agentTo?: string;
   agentThreadId?: string | number;
-  context?: "isolated";
 }) {
   return await spawnSubagentDirect(
     {
@@ -81,7 +81,7 @@ async function spawn(params?: {
         : {}),
       ...(params?.thread ? { thread: true } : {}),
       ...(params?.mode ? { mode: params.mode } : {}),
-      ...(params?.context ? { context: params.context } : {}),
+      context: params?.context ?? "isolated",
     },
     {
       agentSessionKey: params?.agentSessionKey ?? "main",
@@ -170,6 +170,9 @@ describe("sessions_spawn subagent lifecycle hooks", () => {
       session: {
         mainKey: "main",
         scope: "per-sender",
+        threadBindings: {
+          defaultSpawnContext: "isolated",
+        },
       },
     });
     const store: Record<string, Record<string, unknown>> = {};
diff --git a/src/agents/subagent-spawn.thread-binding.test.ts b/src/agents/subagent-spawn.thread-binding.test.ts
index 2dd23d02d3d..41fce53eea8 100644
--- a/src/agents/subagent-spawn.thread-binding.test.ts
+++ b/src/agents/subagent-spawn.thread-binding.test.ts
@@ -55,6 +55,11 @@ describe("spawnSubagentDirect thread binding delivery", () => {
         },
         list: [{ id: "main", workspace: "/tmp/workspace-main" }],
       },
+      session: {
+        threadBindings: {
+          defaultSpawnContext: "isolated",
+        },
+      },
     });
     currentSessionBindingService = { listBySession: () => [] };
     currentDeliveryTargetResolver = (params) => ({
diff --git a/src/agents/subagent-spawn.workspace.test.ts b/src/agents/subagent-spawn.workspace.test.ts
index 828d6e0a42f..589c4808250 100644
--- a/src/agents/subagent-spawn.workspace.test.ts
+++ b/src/agents/subagent-spawn.workspace.test.ts
@@ -53,6 +53,11 @@ function createConfigOverride(overrides?: Record<string, unknown>) {
         },
       ],
     },
+    session: {
+      threadBindings: {
+        defaultSpawnContext: "isolated",
+      },
+    },
     ...overrides,
   });
 }
diff --git a/src/commands/channel-setup/workspace-shadow-bypass.test.ts b/src/commands/channel-setup/workspace-shadow-bypass.test.ts
index a3749cbd865..2ebc81f80a7 100644
--- a/src/commands/channel-setup/workspace-shadow-bypass.test.ts
+++ b/src/commands/channel-setup/workspace-shadow-bypass.test.ts
@@ -18,6 +18,7 @@ const listChannelPluginCatalogEntries = vi.hoisted(() => vi.fn((_opts?: unknown)
 const listChatChannels = vi.hoisted(() => vi.fn((): unknown[] => []));
 const loadPluginManifestRegistry = vi.hoisted(() => vi.fn());
 const loadPluginRegistrySnapshot = vi.hoisted(() => vi.fn());
+const loadPluginRegistrySnapshotWithMetadata = vi.hoisted(() => vi.fn());
 const listPluginContributionIds = vi.hoisted(() => vi.fn((_params?: unknown): string[] => []));
 const applyPluginAutoEnable = vi.hoisted(() =>
   vi.fn(({ config }: { config: unknown }) => ({
@@ -44,11 +45,8 @@ vi.mock("../../plugins/plugin-registry.js", () => ({
   loadPluginManifestRegistryForPluginRegistry: (...args: unknown[]) =>
     loadPluginManifestRegistry(...args),
   loadPluginRegistrySnapshot: (...args: unknown[]) => loadPluginRegistrySnapshot(...args),
-  loadPluginRegistrySnapshotWithMetadata: (...args: unknown[]) => ({
-    source: "derived",
-    snapshot: loadPluginRegistrySnapshot(...args),
-    diagnostics: [],
-  }),
+  loadPluginRegistrySnapshotWithMetadata: (...args: unknown[]) =>
+    loadPluginRegistrySnapshotWithMetadata(...args),
   listPluginContributionIds: (...args: unknown[]) => listPluginContributionIds(...args),
 }));
 vi.mock("../../config/plugin-auto-enable.js", () => ({
@@ -78,6 +76,11 @@ beforeEach(() => {
     plugins: [],
     diagnostics: [],
   });
+  loadPluginRegistrySnapshotWithMetadata.mockImplementation((...args: unknown[]) => ({
+    snapshot: loadPluginRegistrySnapshot(...args),
+    source: "derived",
+    diagnostics: [],
+  }));
   listPluginContributionIds.mockReturnValue([]);
   listChatChannels.mockReturnValue([]);
 });
diff --git a/src/plugins/capability-provider-runtime.test.ts b/src/plugins/capability-provider-runtime.test.ts
index 095dc561a29..1e99ab44df6 100644
--- a/src/plugins/capability-provider-runtime.test.ts
+++ b/src/plugins/capability-provider-runtime.test.ts
@@ -33,7 +33,9 @@ const mocks = vi.hoisted(() => ({
   ),
   resolveInstalledManifestRegistryIndexFingerprint: vi.fn(() => "test-installed-index"),
   loadBundledCapabilityRuntimeRegistry: vi.fn(),
-  loadPluginRegistrySnapshot: vi.fn<() => { plugins: Array<Record<string, unknown>> }>(() => ({
+  loadPluginRegistrySnapshot: vi.fn<
+    (_params?: unknown) => { plugins: Array<Record<string, unknown>> }
+  >(() => ({
     plugins: [],
   })),
   withBundledPluginAllowlistCompat: vi.fn(
@@ -65,13 +67,21 @@ vi.mock("./manifest-registry-installed.js", () => ({
     mocks.resolveInstalledManifestRegistryIndexFingerprint,
 }));
 
+vi.mock("./manifest-registry.js", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("./manifest-registry.js")>();
+  return {
+    ...actual,
+    loadPluginManifestRegistry: mocks.loadPluginManifestRegistry,
+  };
+});
+
 vi.mock("./plugin-registry.js", async (importOriginal) => {
   const actual = await importOriginal<typeof import("./plugin-registry.js")>();
   return {
     ...actual,
     loadPluginRegistrySnapshot: mocks.loadPluginRegistrySnapshot,
     loadPluginRegistrySnapshotWithMetadata: (params?: { index?: unknown }) => {
-      const snapshot = (params?.index ?? mocks.loadPluginRegistrySnapshot()) as {
+      const snapshot = (params?.index ?? mocks.loadPluginRegistrySnapshot(params)) as {
         plugins?: Array<Record<string, unknown>>;
       };
       return {
@@ -138,8 +148,6 @@ function expectBundledCompatLoadPath(params: {
     expect.objectContaining({
       config: params.cfg,
       env: process.env,
-      includeDisabled: true,
-      index: expect.any(Object),
     }),
   );
   expect(mocks.withBundledPluginEnablementCompat).toHaveBeenCalledWith({
@@ -1102,8 +1110,6 @@ describe("resolvePluginCapabilityProviders", () => {
       expect.objectContaining({
         config: {},
         env: process.env,
-        includeDisabled: true,
-        index: expect.any(Object),
       }),
     );
     expect(mocks.resolveRuntimePluginRegistry).toHaveBeenCalledWith({
@@ -1230,8 +1236,6 @@ describe("resolvePluginCapabilityProviders", () => {
       expect.objectContaining({
         config: cfg,
         env: process.env,
-        includeDisabled: true,
-        index: expect.any(Object),
       }),
     );
     expect(mocks.withBundledPluginAllowlistCompat).toHaveBeenCalledWith({
@@ -1265,8 +1269,6 @@ describe("resolvePluginCapabilityProviders", () => {
       expect.objectContaining({
         config: {},
         env: process.env,
-        includeDisabled: true,
-        index: expect.any(Object),
       }),
     );
     expect(mocks.resolveRuntimePluginRegistry).toHaveBeenCalledWith();
diff --git a/src/plugins/migration-provider-runtime.test.ts b/src/plugins/migration-provider-runtime.test.ts
index f152d030344..2495c56bc6e 100644
--- a/src/plugins/migration-provider-runtime.test.ts
+++ b/src/plugins/migration-provider-runtime.test.ts
@@ -33,7 +33,9 @@ const mocks = vi.hoisted(() => ({
   loadPluginManifestRegistry: vi.fn<(params?: Record<string, unknown>) => MockManifestRegistry>(
     () => createEmptyMockManifestRegistry(),
   ),
-  loadPluginRegistrySnapshot: vi.fn<() => MockPluginIndex>(() => createMockPluginIndex([])),
+  loadPluginRegistrySnapshot: vi.fn<(_params?: unknown) => MockPluginIndex>(() =>
+    createMockPluginIndex([]),
+  ),
   loadPluginRegistrySnapshotWithMetadata: vi.fn((params?: { index?: MockPluginIndex }) => ({
     source: params?.index ? "provided" : "derived",
     snapshot: params?.index ?? createMockPluginIndex([]),
@@ -61,7 +63,7 @@ vi.mock("./plugin-registry.js", () => ({
 
 vi.mock("./manifest-registry-installed.js", () => ({
   loadPluginManifestRegistryForInstalledIndex: mocks.loadPluginManifestRegistry,
-  resolveInstalledManifestRegistryIndexFingerprint: () => "test-index",
+  resolveInstalledManifestRegistryIndexFingerprint: () => "test-installed-index",
 }));
 
 vi.mock("./bundled-compat.js", () => ({
diff --git a/src/plugins/web-fetch-providers.runtime.test.ts b/src/plugins/web-fetch-providers.runtime.test.ts
index 7d80b69a36d..ff6ed2e3943 100644
--- a/src/plugins/web-fetch-providers.runtime.test.ts
+++ b/src/plugins/web-fetch-providers.runtime.test.ts
@@ -95,6 +95,18 @@ function createRuntimeWebFetchProvider() {
 
 describe("resolvePluginWebFetchProviders", () => {
   beforeAll(async () => {
+    vi.doMock("./plugin-registry.js", async () => {
+      const actual =
+        await vi.importActual<typeof import("./plugin-registry.js")>("./plugin-registry.js");
+      return {
+        ...actual,
+        loadPluginRegistrySnapshotWithMetadata: () => ({
+          snapshot: { plugins: [], diagnostics: [] },
+          source: "derived",
+          diagnostics: [],
+        }),
+      };
+    });
     loaderModule = await import("./loader.js");
     manifestRegistryModule = await import("./manifest-registry.js");
     webFetchProvidersSharedModule = await import("./web-fetch-providers.shared.js");
@@ -189,7 +201,7 @@ describe("resolvePluginWebFetchProviders", () => {
       workspaceDir: DEFAULT_WORKSPACE,
       env,
       onlyPluginIds: ["firecrawl"],
-      cache: false,
+      cache: true,
       activate: false,
     });
     const registry = createEmptyPluginRegistry();
@@ -226,7 +238,7 @@ describe("resolvePluginWebFetchProviders", () => {
       workspaceDir: DEFAULT_WORKSPACE,
       env,
       onlyPluginIds: ["firecrawl"],
-      cache: false,
+      cache: true,
       activate: false,
     });
     const registry = createEmptyPluginRegistry();
diff --git a/src/plugins/web-search-providers.runtime.test.ts b/src/plugins/web-search-providers.runtime.test.ts
index 6ae9ea573b2..4ba4c07e6f4 100644
--- a/src/plugins/web-search-providers.runtime.test.ts
+++ b/src/plugins/web-search-providers.runtime.test.ts
@@ -304,7 +304,7 @@ function createActiveBraveRegistryFixture(params?: {
     workspaceDir: DEFAULT_WEB_SEARCH_WORKSPACE,
     env,
     onlyPluginIds: ["brave"],
-    cache: false,
+    cache: true,
     activate: false,
   });
   const registry = createEmptyPluginRegistry();
@@ -326,6 +326,16 @@ describe("resolvePluginWebSearchProviders", () => {
   beforeAll(async () => {
     loadPluginManifestRegistryMock = vi.fn<LoadPluginManifestRegistryForPluginRegistry>();
     loadInstalledPluginManifestRegistryMock = vi.fn<LoadPluginManifestRegistryForInstalledIndex>();
+    vi.doMock("./manifest-registry.js", async () => {
+      const actual =
+        await vi.importActual<typeof import("./manifest-registry.js")>("./manifest-registry.js");
+      return {
+        ...actual,
+        loadPluginManifestRegistry: (
+          ...args: Parameters<LoadPluginManifestRegistryForPluginRegistry>
+        ) => loadPluginManifestRegistryMock(...args),
+      };
+    });
     vi.doMock("./plugin-registry.js", async () => {
       const actual =
         await vi.importActual<typeof import("./plugin-registry.js")>("./plugin-registry.js");