feat(calendar): order calendars by sortOrder and move them from the drawer

Calendars were listed in the order the server returns them (creation
order on Stalwart) and sortOrder was never read. Sort them like the
webmail now does and as JMAP Calendars asks: lower sortOrder first,
equal sortOrder by name (case- and accent-insensitive, numbers by
value), each account's calendars kept together. The store keeps the list
sorted, so the drawer, the event editor and the other pickers agree.

The drawer's long-press panel gains Move up / Move down for the user's
own calendars. A move renumbers that account's calendars 1, 2, 3... and
writes sortOrder only where it changes; the panel stays open so a
calendar can be moved several places.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/components/calendar/CalendarSidebarDrawer.tsx

@@ -12,7 +12,7 @@ import {
 } from 'react-native';
 import { SafeAreaView } from 'react-native-safe-area-context';
 import {
-  Check, X, Upload, Rss, Shuffle, Star, Plus, Pencil, Share2, Eraser, Trash2, RefreshCw,
+  Check, X, Upload, Rss, Shuffle, Star, Plus, Pencil, Share2, Eraser, Trash2, RefreshCw, ArrowUp, ArrowDown,
   type AppIcon,
 } from '../icons';
 import type { Calendar } from '../../api/types';
@@ -55,6 +55,9 @@ interface CalendarSidebarDrawerProps {
   onShare?: (calendar: Calendar) => void;
   onClear?: (calendar: Calendar) => void;
   onDelete?: (calendar: Calendar) => void;
+  // Move one of the user's own calendars next to `targetId`, a neighbour in
+  // the same section (before it when moving up, after it when moving down).
+  onMove?: (calendar: Calendar, targetId: string) => void;
   // Client-side iCal subscriptions are managed from the subscriptions sheet.
   isSubscriptionCalendar?: (calendarId: string) => boolean;
 }
@@ -79,6 +82,7 @@ export function CalendarSidebarDrawer({
   onShare,
   onClear,
   onDelete,
+  onMove,
   isSubscriptionCalendar,
 }: CalendarSidebarDrawerProps) {
   const c = useColors();
@@ -148,6 +152,7 @@ export function CalendarSidebarDrawer({
     onShare,
     onClear,
     onDelete,
+    onMove,
     isSubscriptionCalendar,
   };
 
@@ -284,6 +289,7 @@ function Section({
   onShare,
   onClear,
   onDelete,
+  onMove,
   isSubscriptionCalendar,
 }: {
   title: string;
@@ -299,11 +305,14 @@ function Section({
   onShare?: (calendar: Calendar) => void;
   onClear?: (calendar: Calendar) => void;
   onDelete?: (calendar: Calendar) => void;
+  onMove?: (calendar: Calendar, targetId: string) => void;
   isSubscriptionCalendar?: (calendarId: string) => boolean;
 }) {
   const c = useColors();
   const styles = React.useMemo(() => makeStyles(c), [c]);
   const t = useLocaleStore((s) => s.t);
+  // Neighbours a calendar can move past: the server calendars of this section.
+  const orderable = calendars.filter((cal) => cal.id !== BIRTHDAY_CALENDAR_ID);
   return (
     <View style={styles.section}>
       <Text style={styles.sectionTitle}>{title}</Text>
@@ -320,7 +329,11 @@ function Section({
         const canClear = !!onClear && isOwn && isWritableCalendar(cal);
         // Like webmail: the default calendar and shared calendars can't be deleted.
         const canDelete = !!onDelete && isOwn && !cal.isDefault && (!cal.myRights || cal.myRights.mayDelete !== false);
-        const hasActions = canSetDefault || canRecolor || canRename || canShare || canClear || canDelete;
+        const orderIndex = orderable.indexOf(cal);
+        const previousId = isOwn && orderIndex > 0 ? orderable[orderIndex - 1].id : undefined;
+        const nextId = isOwn && orderIndex >= 0 ? orderable[orderIndex + 1]?.id : undefined;
+        const canMove = !!onMove && (!!previousId || !!nextId);
+        const hasActions = canSetDefault || canRecolor || canRename || canShare || canClear || canDelete || canMove;
         const expanded = expandedId === cal.id && hasActions;
         return (
           <View key={cal.id}>
@@ -355,6 +368,27 @@ function Section({
 
             {expanded && (
               <View style={styles.actionsPanel}>
+                {/* The panel stays open so a calendar can be moved several places. */}
+                {canMove && previousId && (
+                  <Pressable
+                    onPress={() => onMove!(cal, previousId)}
+                    style={({ pressed }) => [styles.panelRow, pressed && styles.rowPressed]}
+                    accessibilityRole="button"
+                  >
+                    <ArrowUp size={16} color={c.textSecondary} />
+                    <Text style={styles.panelRowText}>{t('settings.account.accounts.move_up', 'Move up')}</Text>
+                  </Pressable>
+                )}
+                {canMove && nextId && (
+                  <Pressable
+                    onPress={() => onMove!(cal, nextId)}
+                    style={({ pressed }) => [styles.panelRow, pressed && styles.rowPressed]}
+                    accessibilityRole="button"
+                  >
+                    <ArrowDown size={16} color={c.textSecondary} />
+                    <Text style={styles.panelRowText}>{t('settings.account.accounts.move_down', 'Move down')}</Text>
+                  </Pressable>
+                )}
                 {canSetDefault && (
                   <Pressable
                     onPress={() => { onExpand(null); onSetDefault!(cal); }}