fix(journey): keep the picker's date headings chronological, and name any provider

Since the provider picker started sorting by distance to the entry, the date
groups were built from the already-sorted list, so first-seen order put the day
holding the nearest photo at the top and the headings stopped reading in order.
Grouping now sorts its own output; the order within a day is untouched, so the
distance sort still does its job where it belongs.

The picker also called every non-Immich provider "Synology Photos". It now
falls back to the provider's own id, the way the gallery view already did.

client/src/components/Journey/JourneyDetailPageProviderPicker.tsx

@@ -167,7 +167,7 @@ export function ProviderPicker({ provider, userId, entries, trips, existingAsset
         {/* Header */}
         {!embedded && <div className="flex items-center justify-between px-6 py-4 border-b border-zinc-200 dark:border-zinc-700 flex-shrink-0">
           <h2 className="text-[16px] font-bold text-zinc-900 dark:text-white">
-            {provider === 'immich' ? 'Immich' : 'Synology Photos'}
+            {provider === 'immich' ? 'Immich' : provider === 'synologyphotos' ? 'Synology Photos' : provider}
           </h2>
           <button onClick={onClose} className="w-8 h-8 rounded-lg flex items-center justify-center text-zinc-400 hover:bg-zinc-100 dark:hover:bg-zinc-800">
             <X size={16} />

client/src/pages/journeyDetail/JourneyDetailPage.helpers.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest';
-import { distanceBetweenGeoPoints, sortProviderPhotos } from './JourneyDetailPage.helpers';
+import { distanceBetweenGeoPoints, groupPhotosByDate, sortProviderPhotos } from './JourneyDetailPage.helpers';
 
 describe('Journey provider photo ranking', () => {
   it('places GPS photos nearest the selected Journey location and keeps photos without GPS', () => {
@@ -25,3 +25,31 @@ describe('Journey provider photo ranking', () => {
     expect(distanceBetweenGeoPoints({ lat: 41.9, lng: 12.5 }, { lat: 41.9, lng: 12.5 })).toBe(0);
   });
 });
+
+describe('Journey provider photo grouping', () => {
+  it('orders the date headings newest first, whatever order the photos arrive in', () => {
+    const photos = [
+      { id: 'b', takenAt: '2026-03-14T09:00:00Z' },
+      { id: 'a', takenAt: '2026-03-16T09:00:00Z' },
+      { id: 'c', takenAt: '2026-03-15T09:00:00Z' },
+    ];
+    expect(groupPhotosByDate(photos).map((g) => g.date)).toEqual(['2026-03-16', '2026-03-15', '2026-03-14']);
+  });
+
+  it('keeps the distance sort inside a day but not across days', () => {
+    // What sortProviderPhotos hands over: nearest first, so the 14th leads the list.
+    const sorted = [
+      { id: 'near', takenAt: '2026-03-14T10:00:00Z' },
+      { id: 'mid', takenAt: '2026-03-16T10:00:00Z' },
+      { id: 'far', takenAt: '2026-03-14T11:00:00Z' },
+    ];
+    const groups = groupPhotosByDate(sorted);
+    expect(groups.map((g) => g.date)).toEqual(['2026-03-16', '2026-03-14']);
+    expect(groups[1].assets.map((a: { id: string }) => a.id)).toEqual(['near', 'far']);
+  });
+
+  it('sorts photos without a date to the end', () => {
+    const photos = [{ id: 'x' }, { id: 'y', takenAt: '2026-03-16T09:00:00Z' }];
+    expect(groupPhotosByDate(photos).map((g) => g.date)).toEqual(['2026-03-16', '__unknown__']);
+  });
+});

client/src/pages/journeyDetail/JourneyDetailPage.helpers.ts

@@ -66,7 +66,17 @@ export function groupPhotosByDate(photos: any[]): { date: string; label: string;
     if (!map.has(key)) map.set(key, [])
     map.get(key)!.push(asset)
   }
-  return [...map.entries()].map(([date, assets]) => ({
+  // Group order must not depend on the order of `photos`. Once the caller sorts by
+  // distance to the entry, first-seen order would put the day holding the nearest
+  // photo first and the date headings would stop reading chronologically. Order
+  // within a day is left as handed in, so the distance sort still applies there.
+  return [...map.entries()]
+    .sort((a, b) => {
+      if (a[0] === '__unknown__') return 1
+      if (b[0] === '__unknown__') return -1
+      return b[0].localeCompare(a[0])
+    })
+    .map(([date, assets]) => ({
     date,
     label: date === '__unknown__'
       ? 'Unknown date'