feat: multi-select category filter, performance fixes, check-in/out order

- Category filter is now a multi-select dropdown with checkboxes
- PlaceAvatar: replace 200ms polling intervals with event-based
  notification + React.memo for major performance improvement
- Map photo fetches: concurrency limited to 3 + lazy loading on images
- PlacesSidebar: content-visibility + useMemo for smooth scrolling
- Accommodation labels: check-out now appears before check-in on same day
- Timed places auto-sort chronologically when time is added

client/src/components/Planner/DayPlanSidebar.tsx

@@ -793,6 +793,18 @@ export default function DayPlanSidebar({
                       </button>
                       {(() => {
                         const dayAccs = accommodations.filter(a => day.id >= a.start_day_id && day.id <= a.end_day_id)
+                          // Sort: check-out first, then ongoing stays, then check-in last
+                          .sort((a, b) => {
+                            const aIsOut = a.end_day_id === day.id && a.start_day_id !== day.id
+                            const bIsOut = b.end_day_id === day.id && b.start_day_id !== day.id
+                            const aIsIn = a.start_day_id === day.id
+                            const bIsIn = b.start_day_id === day.id
+                            if (aIsOut && !bIsOut) return -1
+                            if (!aIsOut && bIsOut) return 1
+                            if (aIsIn && !bIsIn) return 1
+                            if (!aIsIn && bIsIn) return -1
+                            return 0
+                          })
                         if (dayAccs.length === 0) return null
                         return dayAccs.map(acc => {
                           const isCheckIn = acc.start_day_id === day.id