diff --git a/src/agents/model-thinking-default.ts b/src/agents/model-thinking-default.ts
index 5479152253d..de415432a23 100644
--- a/src/agents/model-thinking-default.ts
+++ b/src/agents/model-thinking-default.ts
@@ -18,9 +18,11 @@ export function resolveThinkingDefault(params: {
 }): ThinkLevel {
   const normalizedProvider = normalizeProviderId(params.provider);
   const normalizedModel = normalizeLowercaseStringOrEmpty(params.model).replace(/\./g, "-");
-  const catalogCandidate = params.catalog?.find(
-    (entry) => entry.provider === params.provider && entry.id === params.model,
-  );
+  const catalogCandidate = Array.isArray(params.catalog)
+    ? params.catalog.find(
+        (entry) => entry.provider === params.provider && entry.id === params.model,
+      )
+    : undefined;
   const configuredModels = params.cfg.agents?.defaults?.models;
   const canonicalKey = modelKey(params.provider, params.model);
   const legacyKey = legacyModelKey(params.provider, params.model);
diff --git a/src/commands/agent/session.test.ts b/src/commands/agent/session.test.ts
index c970b8a59bd..b030ac1522c 100644
--- a/src/commands/agent/session.test.ts
+++ b/src/commands/agent/session.test.ts
@@ -8,17 +8,24 @@ const mocks = vi.hoisted(() => ({
   listAgentIds: vi.fn(),
 }));
 
-vi.mock("../../config/sessions.js", async () => {
-  const actual = await vi.importActual<typeof import("../../config/sessions.js")>(
-    "../../config/sessions.js",
+vi.mock("../../config/sessions/main-session.js", async () => {
+  const actual = await vi.importActual<typeof import("../../config/sessions/main-session.js")>(
+    "../../config/sessions/main-session.js",
   );
   return {
     ...actual,
-    loadSessionStore: mocks.loadSessionStore,
-    resolveStorePath: mocks.resolveStorePath,
+    resolveExplicitAgentSessionKey: () => undefined,
   };
 });
 
+vi.mock("../../config/sessions/paths.js", () => ({
+  resolveStorePath: mocks.resolveStorePath,
+}));
+
+vi.mock("../../config/sessions/store-load.js", () => ({
+  loadSessionStore: mocks.loadSessionStore,
+}));
+
 vi.mock("../../agents/agent-scope.js", () => ({
   listAgentIds: mocks.listAgentIds,
 }));
diff --git a/src/cron/isolated-agent.hook-content-wrapping.test.ts b/src/cron/isolated-agent.hook-content-wrapping.test.ts
index bbf78536cd7..e3c51c815ab 100644
--- a/src/cron/isolated-agent.hook-content-wrapping.test.ts
+++ b/src/cron/isolated-agent.hook-content-wrapping.test.ts
@@ -1,7 +1,6 @@
 import "./isolated-agent.mocks.js";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { loadModelCatalog } from "../agents/model-catalog.js";
-import * as modelSelection from "../agents/model-selection.js";
 import { runEmbeddedPiAgent } from "../agents/pi-embedded.js";
 import {
   DEFAULT_MESSAGE,
@@ -10,10 +9,11 @@ import {
   runCronTurn,
   withTempHome,
 } from "./isolated-agent.turn-test-helpers.js";
+import * as isolatedAgentRunRuntime from "./isolated-agent/run.runtime.js";
 
 describe("runCronIsolatedAgentTurn hook content wrapping", () => {
   beforeEach(() => {
-    vi.spyOn(modelSelection, "resolveThinkingDefault").mockReturnValue("off");
+    vi.spyOn(isolatedAgentRunRuntime, "resolveThinkingDefault").mockReturnValue("off");
     vi.mocked(runEmbeddedPiAgent).mockClear();
     vi.mocked(loadModelCatalog).mockResolvedValue([]);
   });
diff --git a/src/cron/isolated-agent.model-formatting.test.ts b/src/cron/isolated-agent.model-formatting.test.ts
index 68d22b496af..3d58187906e 100644
--- a/src/cron/isolated-agent.model-formatting.test.ts
+++ b/src/cron/isolated-agent.model-formatting.test.ts
@@ -1,4 +1,5 @@
 import { beforeEach, describe, expect, it, vi } from "vitest";
+import { DEFAULT_MODEL, DEFAULT_PROVIDER } from "../agents/defaults.js";
 
 const {
   loadModelCatalogMock,
@@ -49,8 +50,6 @@ vi.mock("../agents/model-selection.js", () => ({
 import { resolveCronModelSelection } from "./isolated-agent/model-selection.js";
 
 const DEFAULT_MESSAGE = "do it";
-const DEFAULT_PROVIDER = "anthropic";
-const DEFAULT_MODEL = "claude-opus-4-6";
 
 type AgentTurnPayload = {
   kind: "agentTurn";
@@ -88,7 +87,7 @@ function parseModelRef(raw: string): { provider: string; model: string } | { err
   }
 
   const provider = providerRaw === "bedrock" ? "amazon-bedrock" : providerRaw;
-  const model = provider === "anthropic" && modelRaw === "opus-4.5" ? "claude-opus-4-6" : modelRaw;
+  const model = provider === "anthropic" && modelRaw === "opus-4.5" ? "claude-opus-4-5" : modelRaw;
   return { provider, model };
 }
 
@@ -204,7 +203,7 @@ describe("cron model formatting and precedence edge cases", () => {
         selectModel({
           payload: { kind: "agentTurn", message: DEFAULT_MESSAGE, model: "openai/" },
         }),
-      ).resolves.toEqual({ ok: false, error: "invalid model" });
+      ).resolves.toEqual({ ok: false, error: "invalid model: openai/" });
     });
 
     it("rejects model with leading slash (empty provider)", async () => {
@@ -212,7 +211,7 @@ describe("cron model formatting and precedence edge cases", () => {
         selectModel({
           payload: { kind: "agentTurn", message: DEFAULT_MESSAGE, model: "/gpt-4.1-mini" },
         }),
-      ).resolves.toEqual({ ok: false, error: "invalid model" });
+      ).resolves.toEqual({ ok: false, error: "invalid model: /gpt-4.1-mini" });
     });
 
     it("normalizes provider casing", async () => {
@@ -237,7 +236,7 @@ describe("cron model formatting and precedence edge cases", () => {
             model: "anthropic/opus-4.5",
           },
         },
-        { provider: "anthropic", model: "claude-opus-4-6" },
+        { provider: "anthropic", model: "claude-opus-4-5" },
       );
     });
 
diff --git a/src/cron/isolated-agent.model-overrides.test.ts b/src/cron/isolated-agent.model-overrides.test.ts
index 9a976137078..4db5f5fa2e0 100644
--- a/src/cron/isolated-agent.model-overrides.test.ts
+++ b/src/cron/isolated-agent.model-overrides.test.ts
@@ -1,7 +1,6 @@
 import "./isolated-agent.mocks.js";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { loadModelCatalog } from "../agents/model-catalog.js";
-import * as modelSelection from "../agents/model-selection.js";
 import { runEmbeddedPiAgent } from "../agents/pi-embedded.js";
 import {
   DEFAULT_AGENT_TURN_PAYLOAD,
@@ -13,10 +12,11 @@ import {
   runTurnWithStoredModelOverride,
   withTempHome,
 } from "./isolated-agent.turn-test-helpers.js";
+import * as isolatedAgentRunRuntime from "./isolated-agent/run.runtime.js";
 
 describe("runCronIsolatedAgentTurn model overrides", () => {
   beforeEach(() => {
-    vi.spyOn(modelSelection, "resolveThinkingDefault").mockReturnValue("off");
+    vi.spyOn(isolatedAgentRunRuntime, "resolveThinkingDefault").mockReturnValue("off");
     vi.mocked(runEmbeddedPiAgent).mockClear();
     vi.mocked(loadModelCatalog).mockResolvedValue([]);
   });
@@ -176,7 +176,7 @@ describe("runCronIsolatedAgentTurn model overrides", () => {
 
   it("passes through the resolved default thinking level", async () => {
     await withTempHome(async (home) => {
-      vi.mocked(modelSelection.resolveThinkingDefault).mockReturnValueOnce("low");
+      vi.mocked(isolatedAgentRunRuntime.resolveThinkingDefault).mockReturnValueOnce("low");
 
       await runCronTurn(home, {
         jobPayload: DEFAULT_AGENT_TURN_PAYLOAD,
diff --git a/src/cron/isolated-agent.session-identity.test.ts b/src/cron/isolated-agent.session-identity.test.ts
index 36df45280f4..bd166b23ab0 100644
--- a/src/cron/isolated-agent.session-identity.test.ts
+++ b/src/cron/isolated-agent.session-identity.test.ts
@@ -1,9 +1,7 @@
 import "./isolated-agent.mocks.js";
 import fs from "node:fs/promises";
 import path from "node:path";
-import { beforeEach, describe, expect, it, vi } from "vitest";
-import * as modelSelection from "../agents/model-selection.js";
-import { runEmbeddedPiAgent } from "../agents/pi-embedded.js";
+import { beforeEach, describe, expect, it } from "vitest";
 import { runCronIsolatedAgentTurn } from "./isolated-agent.js";
 import { makeCfg, makeJob, writeSessionStore } from "./isolated-agent.test-harness.js";
 import {
@@ -16,13 +14,17 @@ import {
   withTempHome,
 } from "./isolated-agent.turn-test-helpers.js";
 import { setupRunCronIsolatedAgentTurnSuite } from "./isolated-agent/run.suite-helpers.js";
+import {
+  mockRunCronFallbackPassthrough,
+  runEmbeddedPiAgentMock,
+} from "./isolated-agent/run.test-harness.js";
 
 setupRunCronIsolatedAgentTurnSuite();
 
 describe("runCronIsolatedAgentTurn session identity", () => {
   beforeEach(() => {
-    vi.spyOn(modelSelection, "resolveThinkingDefault").mockReturnValue("off");
-    vi.mocked(runEmbeddedPiAgent).mockClear();
+    mockRunCronFallbackPassthrough();
+    runEmbeddedPiAgentMock.mockClear();
   });
 
   it("passes resolved agentDir to runEmbeddedPiAgent", async () => {
@@ -32,7 +34,7 @@ describe("runCronIsolatedAgentTurn session identity", () => {
       });
 
       expect(res.status).toBe("ok");
-      const call = vi.mocked(runEmbeddedPiAgent).mock.calls.at(-1)?.[0] as {
+      const call = runEmbeddedPiAgentMock.mock.calls.at(-1)?.[0] as {
         agentDir?: string;
       };
       expect(call?.agentDir).toBe(path.join(home, ".openclaw", "agents", "main", "agent"));
@@ -45,7 +47,7 @@ describe("runCronIsolatedAgentTurn session identity", () => {
         jobPayload: DEFAULT_AGENT_TURN_PAYLOAD,
       });
 
-      const call = vi.mocked(runEmbeddedPiAgent).mock.calls.at(-1)?.[0] as {
+      const call = runEmbeddedPiAgentMock.mock.calls.at(-1)?.[0] as {
         prompt?: string;
       };
       const lines = call?.prompt?.split("\n") ?? [];
@@ -93,7 +95,7 @@ describe("runCronIsolatedAgentTurn session identity", () => {
       });
 
       expect(res.status).toBe("ok");
-      const call = vi.mocked(runEmbeddedPiAgent).mock.calls.at(-1)?.[0] as {
+      const call = runEmbeddedPiAgentMock.mock.calls.at(-1)?.[0] as {
         sessionKey?: string;
         workspaceDir?: string;
         sessionFile?: string;
@@ -109,7 +111,7 @@ describe("runCronIsolatedAgentTurn session identity", () => {
       await runCronTurn(home, {
         jobPayload: DEFAULT_AGENT_TURN_PAYLOAD,
       });
-      const call = vi.mocked(runEmbeddedPiAgent).mock.calls.at(-1)?.[0] as {
+      const call = runEmbeddedPiAgentMock.mock.calls.at(-1)?.[0] as {
         sessionFile?: string;
       };
 
diff --git a/src/cron/isolated-agent/run.test-harness.ts b/src/cron/isolated-agent/run.test-harness.ts
index 162b9b3bb33..eada1c3bf92 100644
--- a/src/cron/isolated-agent/run.test-harness.ts
+++ b/src/cron/isolated-agent/run.test-harness.ts
@@ -143,7 +143,7 @@ vi.mock("./skills-snapshot.runtime.js", () => ({
 }));
 
 vi.mock("./run-model-selection.runtime.js", () => ({
-  DEFAULT_MODEL: "gpt-4",
+  DEFAULT_MODEL: "gpt-5.4",
   DEFAULT_PROVIDER: "openai",
   loadModelCatalog: loadModelCatalogMock,
   getModelRefStatus: getModelRefStatusMock,
@@ -252,7 +252,7 @@ function makeDefaultModelFallbackResult() {
       meta: { agentMeta: { usage: { input: 10, output: 20 } } },
     },
     provider: "openai",
-    model: "gpt-4",
+    model: "gpt-5.4",
   };
 }
 
@@ -292,8 +292,8 @@ function resetRunConfigMocks(): void {
   );
   resolveAgentModelFallbacksOverrideMock.mockReturnValue(undefined);
   resolveAgentSkillsFilterMock.mockReturnValue(undefined);
-  resolveConfiguredModelRefMock.mockReturnValue({ provider: "openai", model: "gpt-4" });
-  resolveAllowedModelRefMock.mockReturnValue({ ref: { provider: "openai", model: "gpt-4" } });
+  resolveConfiguredModelRefMock.mockReturnValue({ provider: "openai", model: "gpt-5.4" });
+  resolveAllowedModelRefMock.mockReturnValue({ ref: { provider: "openai", model: "gpt-5.4" } });
   resolveHooksGmailModelMock.mockReturnValue(null);
   resolveThinkingDefaultMock.mockReturnValue("off");
   getModelRefStatusMock.mockReturnValue({ allowed: false });
@@ -315,7 +315,7 @@ function resetRunConfigMocks(): void {
   isExternalHookSessionMock.mockReturnValue(false);
   resolveHookExternalContentSourceMock.mockReturnValue(undefined);
   getSkillsSnapshotVersionMock.mockReturnValue(42);
-  loadModelCatalogMock.mockResolvedValue({ models: [] });
+  loadModelCatalogMock.mockResolvedValue([]);
   getRemoteSkillEligibilityMock.mockResolvedValue({ remoteSkillsEnabled: false });
 }