Version history, notes on highlights and bookmarks, "you've studied this", prayer journal

- Earlier versions of a study: the server keeps compressed copies (about one per ten minutes of
  editing, the latest 30); Export shows what differs and puts one back (the replaced copy is kept)
- Notes on highlights and bookmarks: synced, merged without loss, in exports and backups
- Reader verse panel lists your studies and chunks that cover the verse, and opens them
- Prayer journal: requests, who for, linked verses, days prayed, answers; synced, in backups
  and the account export; daily prayer reminder through ntfy
- TODO.md lists the ideas not built yet

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/pages/SettingsPage.jsx

@@ -87,6 +87,8 @@ export default function SettingsPage() {
     reminderTime: authUser?.reminderTime ?? '07:00',
     votdEnabled: authUser?.votdEnabled ?? false,
     votdTime: authUser?.votdTime ?? '06:30',
+    prayerEnabled: authUser?.prayerEnabled ?? false,
+    prayerTime: authUser?.prayerTime ?? '20:00',
   });
   const [reminderBusy, setReminderBusy] = useState(false);
   const [reminderError, setReminderError] = useState('');
@@ -428,6 +430,18 @@ export default function SettingsPage() {
                 />
               </label>
             </div>
+            <div className="rounded-xl border border-[var(--r-line)] p-3">
+              <label className="flex items-center gap-2 text-sm font-medium text-[var(--r-text)]">
+                <input type="checkbox" checked={reminderForm.prayerEnabled} onChange={(e) => setReminderForm((f) => ({ ...f, prayerEnabled: e.target.checked }))} className="h-4 w-4 accent-[var(--r-accent)]" />
+                Daily prayer reminder
+              </label>
+              <label className="mt-2 block max-w-xs text-sm font-medium text-[var(--r-text)]">
+                Remind me at
+                <input type="time" value={reminderForm.prayerTime} onChange={(e) => setReminderForm((f) => ({ ...f, prayerTime: e.target.value }))}
+                  className="mt-1 block w-full rounded-xl border border-[var(--r-line)] bg-[var(--r-bg)] px-3 py-2 text-sm text-[var(--r-text)] focus:outline-none focus:ring-2 focus:ring-[var(--r-line)]" />
+              </label>
+              <span className="mt-1 block text-xs text-[var(--r-sub)]">A notification to the same topic listing a few of the requests in your prayer journal. Nothing is sent when there are no open requests.</span>
+            </div>
             {authUser?.votdAvailable && (
               <div className="rounded-xl border border-[var(--r-line)] p-3">
                 <label className="flex items-center gap-2 text-sm font-medium text-[var(--r-text)]">