web: single-pointer selection + post-action focus, video debounce, tags metadata sidebar

Selection: plain arrow nav now clears prior multi-selection so exactly
one tile is ringed at a time; shift-extend still grows from the anchor.
onApprove / onRestore / onDelete advance focus via focusAfter(ids)
before clearing selection, matching onArchive.

Preview: defer mounting <VideoPlayer> by 250ms so arrow-skim across
video tiles doesn't open and immediately cancel range requests; hard-
abort the underlying <video> on unmount so the connection releases.

Tags drill view: right-sidebar metadata wired in (single-photo
RightSidebar, BulkMetadataSidebar for >=2 selected), resizable edge
mirrors the timeline.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/src/routes/+page.svelte

@@ -26,6 +26,7 @@
   import { isAuthenticated } from "$lib/stores/session.svelte";
   import { untrack } from "svelte";
   import {
+    clearSelection,
     isSelected,
     selectRange,
     selection,
@@ -570,6 +571,10 @@
     const destUid = rows[r]?.uids[c];
     if (!destUid) return;
 
+    // Plain arrow nav collapses any prior multi-selection to the cursor
+    // (mirrors gridKeyNav.moveFocus). Shift-extend keeps `ids` growing
+    // from the anchor below.
+    if (!extending) clearSelection();
     setFocused(destUid);
     if (!extending) setAnchor(destUid);
     if (extending && selection.focused) selectRange(destUid);