perf(api): debounce post-SET force update to coalesce rapid changes

The post-SET force update used a leading-lockout debounce: the first
change scheduled a poll, and subsequent changes within the window were
dropped. A poll could therefore fire mid-sequence, and the next change
would schedule a fresh poll - so a burst of interactive adjustments
(power, fan speed, mode) triggered multiple full device polls and burned
extra API calls.

Switch to a trailing debounce that resets the timer on every change, so
a burst collapses into a single poll fired after the last change. The
periodic interval is paused on the first change of a burst and restarted
once the debounced poll completes.

Add integration tests covering both the coalescing of rapid changes and
the single poll for an isolated change.

Author: claude

src/platform.ts

@@ -312,16 +312,20 @@ export class DaikinCloudPlatform implements DynamicPlatformPlugin {
   }
 
   forceUpdateDevices(delay: number = Math.max(0, this.config.forceUpdateDelay || DEFAULT_FORCE_UPDATE_DELAY_MS)) {
-    // Debounce: if a force update is already pending, don't restart timers
+    // Trailing debounce: reset the timer on every change so a burst of rapid
+    // SETs (e.g. toggling power, fan speed and mode in quick succession)
+    // collapses into a single poll fired `delay` ms after the *last* change,
+    // instead of one poll per change. This avoids redundant API calls.
     if (this.forceUpdateTimeout) {
-      this.log.debug('[API Syncing] Force update already pending, skipping duplicate request');
-      return;
+      clearTimeout(this.forceUpdateTimeout);
+      this.log.debug(`[API Syncing] Force update rescheduled (debouncing rapid changes, delayed by ${delay}ms)`);
+    } else {
+      this.log.debug(`[API Syncing] Force update devices data (delayed by ${delay}ms)`);
+      // Pause periodic polling while we wait for the change to settle; it is
+      // restarted once the debounced update fires.
+      clearInterval(this.updateInterval);
     }
 
-    this.log.debug(`[API Syncing] Force update devices data (delayed by ${delay}ms)`);
-
-    clearInterval(this.updateInterval);
-
     this.forceUpdateTimeout = setTimeout(async () => {
       this.forceUpdateTimeout = undefined;
       try {

test/integration/platform.test.ts

@@ -152,6 +152,80 @@ test('DaikinCloudPlatform registers the accessory when its raw device ID is NOT
   expect(registerSpy).toHaveBeenCalled();
 });
 
+test('forceUpdateDevices debounces rapid changes into a single poll fired after the last change', async () => {
+  const mockDevice = {
+    getId: () => 'MOCK_ID',
+    getDescription: () => ({ deviceModel: 'Airco' }),
+    getData: () => 'MOCK_DATE',
+    desc: { managementPoints: [{ embeddedId: 'climateControl', managementPointType: 'climateControl' }] },
+  } as unknown as DaikinCloudDevice;
+
+  MockDaikinCloudController.mockImplementation(function(this: any) {
+    this.getCloudDevices = vi.fn().mockResolvedValue([mockDevice]);
+    this.isAuthenticated = vi.fn().mockReturnValue(true);
+    this.on = vi.fn();
+    this.updateAllDeviceData = vi.fn().mockResolvedValue(undefined);
+  });
+
+  const api = new HomebridgeAPI();
+  const config = new MockPlatformConfig(true);
+  (config as any).forceUpdateDelay = 10000;
+
+  const platform = new DaikinCloudPlatform(new Logger(), config, api);
+  api.signalFinished();
+  await vi.advanceTimersByTimeAsync(100);
+
+  const updateSpy = (platform.controller as any).updateAllDeviceData as ReturnType<typeof vi.fn>;
+  updateSpy.mockClear();
+
+  // Three rapid SETs, each within the 10s debounce window of the previous one.
+  platform.forceUpdateDevices();
+  await vi.advanceTimersByTimeAsync(3000);
+  platform.forceUpdateDevices();
+  await vi.advanceTimersByTimeAsync(3000);
+  platform.forceUpdateDevices();
+
+  // 9s after the last call the timer has not yet elapsed (it was reset each time).
+  await vi.advanceTimersByTimeAsync(9000);
+  expect(updateSpy).not.toHaveBeenCalled();
+
+  // The poll fires exactly once, 10s after the *last* change.
+  await vi.advanceTimersByTimeAsync(1000);
+  expect(updateSpy).toHaveBeenCalledTimes(1);
+});
+
+test('forceUpdateDevices performs a single poll for an isolated change', async () => {
+  const mockDevice = {
+    getId: () => 'MOCK_ID',
+    getDescription: () => ({ deviceModel: 'Airco' }),
+    getData: () => 'MOCK_DATE',
+    desc: { managementPoints: [{ embeddedId: 'climateControl', managementPointType: 'climateControl' }] },
+  } as unknown as DaikinCloudDevice;
+
+  MockDaikinCloudController.mockImplementation(function(this: any) {
+    this.getCloudDevices = vi.fn().mockResolvedValue([mockDevice]);
+    this.isAuthenticated = vi.fn().mockReturnValue(true);
+    this.on = vi.fn();
+    this.updateAllDeviceData = vi.fn().mockResolvedValue(undefined);
+  });
+
+  const api = new HomebridgeAPI();
+  const config = new MockPlatformConfig(true);
+  (config as any).forceUpdateDelay = 10000;
+
+  const platform = new DaikinCloudPlatform(new Logger(), config, api);
+  api.signalFinished();
+  await vi.advanceTimersByTimeAsync(100);
+
+  const updateSpy = (platform.controller as any).updateAllDeviceData as ReturnType<typeof vi.fn>;
+  updateSpy.mockClear();
+
+  platform.forceUpdateDevices();
+  await vi.advanceTimersByTimeAsync(10000);
+
+  expect(updateSpy).toHaveBeenCalledTimes(1);
+});
+
 test('DaikinCloudPlatform with new Altherma accessory', async () => {
   const mockDevice = {
     getId: () => 'MOCK_ID',