refactor: name the merge options and drop their subtext

frontend/src/lib/components/view/batch-operations-toolbar.svelte

@@ -199,27 +199,14 @@
 						>
 							<GitMerge />
 						</DropdownMenu.Trigger>
-						<DropdownMenu.Content class="w-72">
-							<DropdownMenu.Item class="flex-col items-start gap-0.5" onclick={quickMerge}>
-								<span class="flex w-full min-w-0 items-center gap-2">
-									<GitMerge class="size-4 shrink-0" />
-									<span class="truncate">Keep “{selectedBooks[0].title}”</span>
-								</span>
-								<span class="pl-6 text-xs text-wrap text-muted-foreground">
-									Files move onto the book you selected first, which keeps its own metadata.
-								</span>
+						<DropdownMenu.Content>
+							<DropdownMenu.Item onclick={quickMerge}>
+								<GitMerge class="size-4 shrink-0" />
+								Merge into first selected
 							</DropdownMenu.Item>
-							<DropdownMenu.Item
-								class="flex-col items-start gap-0.5"
-								onclick={() => (mergingBooks = selectedBooks)}
-							>
-								<span class="flex items-center gap-2">
-									<SlidersHorizontal class="size-4 shrink-0" />
-									Choose what to keep…
-								</span>
-								<span class="pl-6 text-xs text-wrap text-muted-foreground">
-									Pick the record that survives and resolve the metadata field by field.
-								</span>
+							<DropdownMenu.Item onclick={() => (mergingBooks = selectedBooks)}>
+								<SlidersHorizontal class="size-4 shrink-0" />
+								Manual merge…
 							</DropdownMenu.Item>
 						</DropdownMenu.Content>
 					</DropdownMenu.Root>