feat(frontend): stage Escape in the tag editors to clear, then exit

In the single-file viewer's tag filter, Escape now clears a non-empty
filter first; on an empty filter it blurs and scrolls the preview back
to the top. In the bulk (multi-file) editor it clears, then releases
focus, so only the next Escape reaches the page handler and closes the
popup.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/lib/components/file/BulkTagEditor.svelte

@@ -159,6 +159,20 @@
 				void remove(tag.id);
 				assignedFocusIdx = Math.min(assignedFocusIdx, assignedTags.length - 2);
 			}
+		} else if (e.key === 'Escape') {
+			// Staged exit: a non-empty filter clears first; once empty, Escape
+			// releases focus. Stop propagation so neither step reaches the page's
+			// window handler — only the *next* Escape (with focus already gone) does,
+			// and that one closes the popup.
+			e.preventDefault();
+			e.stopPropagation();
+			if (search) {
+				search = '';
+				assignedFocusIdx = -1;
+			} else {
+				assignedFocusIdx = -1;
+				(e.currentTarget as HTMLInputElement).blur();
+			}
 		}
 	}
 </script>

frontend/src/lib/components/file/FileViewer.svelte

@@ -184,9 +184,17 @@
 	}
 
 	// ---- Keyboard ----
+	let viewerPage = $state<HTMLElement>();
 	let tagsSection = $state<HTMLElement>();
 	let pendingTagFocus = false;
 
+	// Bring the preview back to the top of the scroll container (the overlay, or
+	// the page in the standalone route). scrollIntoView resolves the right
+	// scroller in either case. Called when Escape leaves the tag filter.
+	function revealPreview() {
+		viewerPage?.scrollIntoView({ behavior: 'smooth', block: 'start' });
+	}
+
 	function handleKeydown(e: KeyboardEvent) {
 		if (e.target instanceof HTMLInputElement || e.target instanceof HTMLTextAreaElement) return;
 		if (e.ctrlKey || e.metaKey || e.altKey) return;
@@ -242,7 +250,7 @@
 
 <svelte:window onkeydown={handleKeydown} />
 
-<div class="viewer-page">
+<div class="viewer-page" bind:this={viewerPage}>
 	<!-- Top bar -->
 	<div class="top-bar">
 		<button class="back-btn" onclick={onClose} aria-label="Back to files">
@@ -377,7 +385,7 @@
 			<section class="section" use:tagsSentinel bind:this={tagsSection}>
 				<div class="field-label">Tags</div>
 				{#if tagsLoaded}
-					<TagPicker {fileTags} onAdd={addTag} onRemove={removeTag} />
+					<TagPicker {fileTags} onAdd={addTag} onRemove={removeTag} onExit={revealPreview} />
 				{:else}
 					<p class="tags-loading">Loading tags…</p>
 				{/if}

frontend/src/lib/components/file/TagPicker.svelte

@@ -7,9 +7,12 @@
 		fileTags: Tag[];
 		onAdd: (tagId: string) => Promise<void>;
 		onRemove: (tagId: string) => Promise<void>;
+		/** Called when Escape leaves an already-empty filter, so the viewer can
+		 *  scroll the preview back into view. */
+		onExit?: () => void;
 	}
 
-	let { fileTags, onAdd, onRemove }: Props = $props();
+	let { fileTags, onAdd, onRemove, onExit }: Props = $props();
 
 	let allTags = $state<Tag[]>([]);
 	let search = $state('');
@@ -110,11 +113,18 @@
 				assignedFocusIdx = Math.min(assignedFocusIdx, filteredAssigned.length - 2);
 			}
 		} else if (e.key === 'Escape') {
-			// Let the keyboard leave the field: blur back to the page so arrow keys
-			// and Escape reach the viewer again (e.g. a second Esc closes it).
 			e.preventDefault();
+			if (search) {
+				// Non-empty filter: just clear it, keeping focus for more editing.
+				search = '';
+				assignedFocusIdx = -1;
+				return;
+			}
+			// Empty: blur back to the page (so arrow keys and a further Escape reach
+			// the viewer) and let it scroll the preview back into view.
 			assignedFocusIdx = -1;
 			(e.currentTarget as HTMLInputElement).blur();
+			onExit?.();
 		}
 	}
 </script>