web: de-brand PhotoPrism references in user-facing copy

Replaces "PhotoPrism" in UI strings (empty states, tooltips, toasts,
log header, login screen) with neutral terms like "the indexer", "the
library", "the server" — accurate regardless of backend. The login
header becomes "Mulimage" and drops the explicit PhotoPrism mention.

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

web/src/routes/review/+page.svelte

@@ -242,10 +242,10 @@
 					<EmptyState icon={Sparkles} title="Nothing to review">
 						{#snippet descriptionSnippet()}
 							<p>
-								PhotoPrism's indexer flags photos with a low quality score for human
-								review. New arrivals with missing EXIF, low resolution, or unknown
-								cameras will land here. The Stacks and Cross-folder tabs above stay
-								available for duplicate cleanup.
+								The indexer flags photos with a low quality score for human review. New
+								arrivals with missing EXIF, low resolution, or unknown cameras will land
+								here. The Stacks and Cross-folder tabs above stay available for
+								duplicate cleanup.
 							</p>
 						{/snippet}
 					</EmptyState>