fix(statusline): re-arm polling when config changes (#1416)

Co-authored-by: Letta Code <noreply@letta.com>

src/tests/cli/statusline-controller.test.ts

@@ -3,6 +3,7 @@ import {
   DEFAULT_STATUS_LINE_DEBOUNCE_MS,
   normalizeStatusLineConfig,
 } from "../../cli/helpers/statusLineConfig";
+import { buildRefreshIntervalPlan } from "../../cli/hooks/useConfigurableStatusLine";
 
 describe("statusline controller-related config", () => {
   test("normalizes debounce and refresh interval defaults", () => {
@@ -29,3 +30,43 @@ describe("statusline controller-related config", () => {
     expect(normalized.debounceMs).toBe(50);
   });
 });
+
+describe("buildRefreshIntervalPlan", () => {
+  test("returns no-op when interval is unchanged", () => {
+    expect(buildRefreshIntervalPlan(null, null)).toEqual({
+      shouldClearExistingInterval: false,
+      shouldArmInterval: false,
+      nextRefreshIntervalMs: null,
+    });
+
+    expect(buildRefreshIntervalPlan(5000, 5000)).toEqual({
+      shouldClearExistingInterval: false,
+      shouldArmInterval: false,
+      nextRefreshIntervalMs: 5000,
+    });
+  });
+
+  test("arms interval when moving from off to polling", () => {
+    expect(buildRefreshIntervalPlan(null, 5000)).toEqual({
+      shouldClearExistingInterval: false,
+      shouldArmInterval: true,
+      nextRefreshIntervalMs: 5000,
+    });
+  });
+
+  test("re-arms interval when polling cadence changes", () => {
+    expect(buildRefreshIntervalPlan(5000, 1000)).toEqual({
+      shouldClearExistingInterval: true,
+      shouldArmInterval: true,
+      nextRefreshIntervalMs: 1000,
+    });
+  });
+
+  test("clears interval when polling is disabled", () => {
+    expect(buildRefreshIntervalPlan(5000, null)).toEqual({
+      shouldClearExistingInterval: true,
+      shouldArmInterval: false,
+      nextRefreshIntervalMs: null,
+    });
+  });
+});