feat: schedule mobile notification quiet hours (Closes #1392)

frontend/index.html

@@ -224,6 +224,12 @@
             <button class="secondary" id="push-test" type="button" hidden>Send test notification</button>
             <label class="push-update-control" for="push-following"><input id="push-following" type="checkbox" /> Notify me when Following changes</label>
             <span class="small" id="push-following-status" role="status" aria-live="polite"></span>
+            <label class="push-update-control" for="push-quiet-hours"><input id="push-quiet-hours" type="checkbox" /> Pause routine alerts on a schedule</label>
+            <div class="push-quiet-hours-times">
+              <label for="push-quiet-start">From <input id="push-quiet-start" type="time" value="22:00" /></label>
+              <label for="push-quiet-end">Until <input id="push-quiet-end" type="time" value="07:00" /></label>
+            </div>
+            <span class="small" id="push-quiet-status" role="status" aria-live="polite"></span>
             <label class="push-update-control" for="push-deadlines"><input id="push-deadlines" type="checkbox" /> Notify me about deadlines</label>
             <label for="push-deadline-hour">Reminder hour <select id="push-deadline-hour" aria-label="Deadline reminder local hour"></select></label>
             <label for="push-deadline-days">Warn me <select id="push-deadline-days" aria-label="Deadline reminder horizon"><option value="0">Due today</option><option value="2" selected>Next 2 days</option><option value="7">Next 7 days</option></select></label>