diff --git a/src/gateway/session-observer-bookkeeping.test.ts b/src/gateway/session-observer-bookkeeping.test.ts
new file mode 100644
index 000000000000..fa14359f5fef
--- /dev/null
+++ b/src/gateway/session-observer-bookkeeping.test.ts
@@ -0,0 +1,41 @@
+import { describe, expect, it } from "vitest";
+
+describe("session observer run bookkeeping", () => {
+  it("bounds dormant runs and preserves revision continuity for evicted entries", async () => {
+    const { rememberSessionObserverDormantRun } = await import("./session-observer-model.js");
+    const runs = new Map();
+    const floors = new Map();
+    for (let index = 0; index < 300; index += 1) {
+      rememberSessionObserverDormantRun(runs, floors, {
+        sessionKey: index === 0 ? "global" : `agent:main:session-${index}`,
+        sessionId: `session-${index}`,
+        runId: `run-${index}`,
+        agentId: index === 0 ? "work" : "main",
+        utilityModelRef: "openai/gpt-test",
+        startedAt: index,
+        lastPersistedAt: undefined,
+        revision: index + 1,
+        digestCount: 1,
+        consecutiveFailures: 0,
+        planProgress: undefined,
+        previousDigest: undefined,
+      });
+    }
+    expect(runs.size).toBe(256);
+    expect(runs.has("run-0")).toBe(false);
+    expect(runs.has("run-299")).toBe(true);
+    expect(floors.get("agent:work:global")?.revision).toBe(1);
+    expect(floors.has("global")).toBe(false);
+  });
+
+  it("bounds disabled-run bookkeeping", async () => {
+    const { rememberSessionObserverDisabledRun } = await import("./session-observer-model.js");
+    const runs = new Set<string>();
+    for (let index = 0; index < 600; index += 1) {
+      rememberSessionObserverDisabledRun(runs, `run-${index}`);
+    }
+    expect(runs.size).toBe(512);
+    expect(runs.has("run-0")).toBe(false);
+    expect(runs.has("run-599")).toBe(true);
+  });
+});
diff --git a/src/gateway/session-observer.test.ts b/src/gateway/session-observer.test.ts
index 44f71ce1b9db..db609908e7c1 100644
--- a/src/gateway/session-observer.test.ts
+++ b/src/gateway/session-observer.test.ts
@@ -1084,43 +1084,3 @@ describe("session observer schema", () => {
     expect(normalized?.assessment).toHaveLength(320);
   });
 });
-
-describe("session observer run bookkeeping", () => {
-  it("bounds dormant runs and preserves revision continuity for evicted entries", async () => {
-    const { rememberSessionObserverDormantRun } = await import("./session-observer-model.js");
-    const runs = new Map();
-    const floors = new Map();
-    for (let index = 0; index < 300; index += 1) {
-      rememberSessionObserverDormantRun(runs, floors, {
-        sessionKey: index === 0 ? "global" : `agent:main:session-${index}`,
-        sessionId: `session-${index}`,
-        runId: `run-${index}`,
-        agentId: index === 0 ? "work" : "main",
-        utilityModelRef: "openai/gpt-test",
-        startedAt: index,
-        lastPersistedAt: undefined,
-        revision: index + 1,
-        digestCount: 1,
-        consecutiveFailures: 0,
-        planProgress: undefined,
-        previousDigest: undefined,
-      });
-    }
-    expect(runs.size).toBe(256);
-    expect(runs.has("run-0")).toBe(false);
-    expect(runs.has("run-299")).toBe(true);
-    expect(floors.get("agent:work:global")?.revision).toBe(1);
-    expect(floors.has("global")).toBe(false);
-  });
-
-  it("bounds disabled-run bookkeeping", async () => {
-    const { rememberSessionObserverDisabledRun } = await import("./session-observer-model.js");
-    const runs = new Set<string>();
-    for (let index = 0; index < 600; index += 1) {
-      rememberSessionObserverDisabledRun(runs, `run-${index}`);
-    }
-    expect(runs.size).toBe(512);
-    expect(runs.has("run-0")).toBe(false);
-    expect(runs.has("run-599")).toBe(true);
-  });
-});