lock: hold the fingerprint scan from a sleep request until PrepareForSleep

fixes #3774

quickshell/Modules/Lock/Pam.qml

@@ -335,7 +335,7 @@ Scope {
         readonly property int verifyStartSlackMs: 10000
         readonly property bool retrying: errorRetry.running
         readonly property int retryInterval: errorRetry.interval
-        readonly property bool allowed: available && SettingsData.enableFprint && root.lockSecured && !root.fprintSuppressedByPrimaryPam && !root.unlockInProgress && !root.u2fPending && !SessionService.preparingForSleep && !IdleService.monitorsOff && tries < SettingsData.maxFprintTries
+        readonly property bool allowed: available && SettingsData.enableFprint && root.lockSecured && !root.fprintSuppressedByPrimaryPam && !root.unlockInProgress && !root.u2fPending && !SessionService.preparingForSleep && !SessionService.sleepRequested && !IdleService.monitorsOff && tries < SettingsData.maxFprintTries
         readonly property string status: {
             if (!available || !SettingsData.enableFprint || !root.lockSecured || root.fprintSuppressedByPrimaryPam)
                 return "disabled";

quickshell/Services/SessionService.qml

@@ -35,6 +35,7 @@ Singleton {
     property bool idleHint: false
     property bool lockedHint: false
     property bool preparingForSleep: false
+    property bool sleepRequested: false
     property string sessionType: ""
     property string userName: ""
     property string seat: ""
@@ -85,6 +86,21 @@ Singleton {
         onTriggered: root.flushPendingSleep()
     }
 
+    Timer {
+        id: sleepRequestTimeout
+        // A refused sleep or a command that skips logind never sends PrepareForSleep.
+        interval: 10000
+        repeat: false
+        onTriggered: root.sleepRequested = false
+    }
+
+    onPreparingForSleepChanged: {
+        if (!preparingForSleep)
+            return;
+        sleepRequestTimeout.stop();
+        sleepRequested = false;
+    }
+
     Process {
         id: detectEnvironmentProcess
         running: false
@@ -506,6 +522,8 @@ printf 'uwsm=%s\nelogind=%s\nloginctl=%s\nsystemctl=%s\nusermgr=%s\nhibernate=%s
 
     function runSleepAction(run) {
         cancelPendingSleep();
+        sleepRequested = true;
+        sleepRequestTimeout.restart();
         if (!SleepLock.shouldWaitForLock(SettingsData.lockBeforeSuspend, IdleService.isSessionLockSecure)) {
             run();
             return;

quickshell/tests/lock/mocks/qs/Services/SessionService.qml

@@ -3,6 +3,7 @@ import QtQuick
 
 QtObject {
     property bool preparingForSleep: false
+    property bool sleepRequested: false
     signal sessionResumed
     signal lidOpened
 }