Don't allow seeking outside clip bounds, use consistent Shift+Wheel to seek 1 second

src/monitor/monitor.cpp

@@ -967,12 +967,13 @@ void Monitor::keyPressEvent(QKeyEvent *event)
 
 void Monitor::slotMouseSeek(int eventDelta, uint modifiers)
 {
-    if ((modifiers & Qt::ControlModifier) != 0u) {
+    if ((modifiers & Qt::ShiftModifier) != 0u) {
         int delta = qRound(pCore->getCurrentFps());
         if (eventDelta > 0) {
             delta = 0 - delta;
         }
-        m_glMonitor->getControllerProxy()->setPosition(m_glMonitor->getCurrentPos() - delta);
+        delta = qMax(0, m_glMonitor->getCurrentPos() - delta);
+        m_glMonitor->getControllerProxy()->setPosition(qMin(delta, m_glMonitor->duration() - 1));
     } else if ((modifiers & Qt::AltModifier) != 0u) {
         if (eventDelta >= 0) {
             emit seekToPreviousSnap();