fix(extension): reconnect via chrome.idle on OS resume / screen unlock

The 24-second keepalive alarm is the only reconnect trigger today, but
Chrome may suspend the MV3 service worker across deep sleep so an alarm
tick can be skipped past system resume. Add chrome.idle.onStateChanged
to wake the worker on the first active signal after lock or sleep.

Fixes #1735

Author: Benjamin-eecs

extension/dist/background.js

@@ -1420,6 +1420,11 @@ chrome.runtime.onStartup.addListener(() => {
   initialize();
 });
 initialize();
+if (chrome.idle?.onStateChanged?.addListener) {
+  chrome.idle.onStateChanged.addListener((newState) => {
+    if (newState === "active") void connect();
+  });
+}
 chrome.alarms.onAlarm.addListener(async (alarm) => {
   if (alarm.name === "keepalive") void connect();
   const leaseKey = leaseKeyFromAlarmName(alarm.name);

extension/manifest.json

@@ -9,6 +9,7 @@
     "cookies",
     "activeTab",
     "alarms",
+    "idle",
     "storage",
     "tabGroups",
     "downloads"

extension/src/background.ts

@@ -1075,6 +1075,16 @@ chrome.runtime.onStartup.addListener(() => {
 // initialize() is idempotent, so lifecycle events remain harmless.
 initialize();
 
+// Reconnect when the user becomes active after OS resume or screen unlock.
+// The keepalive alarm fires every ~24 s, but Chrome may suspend the service
+// worker across long sleeps, so an alarm tick can be skipped past resume.
+// `chrome.idle.onStateChanged` wakes the worker on the first active signal.
+if (chrome.idle?.onStateChanged?.addListener) {
+  chrome.idle.onStateChanged.addListener((newState) => {
+    if (newState === 'active') void connect();
+  });
+}
+
 chrome.alarms.onAlarm.addListener(async (alarm) => {
   if (alarm.name === 'keepalive') void connect();
   const leaseKey = leaseKeyFromAlarmName(alarm.name);