fix: pass visible sequence to openPreview from the click site

Previously the visible photo order was published only via a passive
useEffect on Timeline, which had a timing race: arrow nav in preview
could read a stale or empty sequence and fall back to the raw API
order, breaking visual order navigation in tag mode and after
filter changes.

Fix: openPreview now accepts an optional visibleSequence parameter,
and Timeline's onDoubleClick passes the freshly-computed flat
sequence directly. The store action adopts that sequence as the
authoritative visiblePhotoIds for the preview session, falling back
to the most-recently-published one for paths that don't have a click
site (e.g. the global Space hotkey).

The Timeline still publishes via useEffect for the Space-hotkey
fallback path, but the click path no longer depends on it.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/store/photoStore.ts

@@ -26,7 +26,11 @@ interface PhotoStore {
   setActivePhoto: (id: string | null) => void
   setViewMode: (mode: ViewMode) => void
   setVisiblePhotoIds: (ids: string[]) => void
-  openPreview: (id: string) => void
+  /** Open preview on a specific photo. The visibleSequence (optional)
+   *  is the ordered list of photo ids the user currently sees in the
+   *  timeline; passing it from the click site avoids a race where the
+   *  passive Timeline publisher hasn't updated yet. */
+  openPreview: (id: string, visibleSequence?: string[]) => void
   closePreview: () => void
 }
 
@@ -99,7 +103,19 @@ export const usePhotoStore = create<PhotoStore>((set) => ({
       return { visiblePhotoIds }
     }),
 
-  openPreview: (id) => set({ viewMode: 'preview', activePhotoId: id }),
+  openPreview: (id, visibleSequence) =>
+    set((s) => ({
+      viewMode: 'preview',
+      activePhotoId: id,
+      // Adopt the caller-provided sequence when they pass one. Falls
+      // back to whatever Timeline most recently published, which is
+      // correct for paths like the global Space hotkey that don't have
+      // a click site to compute the sequence from.
+      visiblePhotoIds:
+        visibleSequence && visibleSequence.length > 0
+          ? visibleSequence
+          : s.visiblePhotoIds,
+    })),
 
   closePreview: () => set({ viewMode: 'grid' }),
 }))