feat(volume-browser): phase 3 - editor integration & polish

- Browse and Download buttons on each volume row in the editor table
- Download entire volume as ZIP directly from the editor (no browser needed)
- File type icons for common extensions in browser
- Ephemeral volumes excluded from browse/download actions

web/src/routes/projects/[id]/volumes/+page.svelte

@@ -4,9 +4,13 @@
 	import * as api from '$lib/api';
 	import { toasts } from '$lib/stores/toast';
 	import { t } from '$lib/i18n';
-	import { IconChevronRight, IconPlus, IconEdit, IconTrash, IconCheck, IconX } from '$lib/components/icons';
+	import { IconChevronRight, IconPlus, IconEdit, IconTrash, IconCheck, IconX, IconSearch, IconExternalLink } from '$lib/components/icons';
 	import Skeleton from '$lib/components/Skeleton.svelte';
 
+	function downloadUrl(volId: string): string {
+		return api.volumeDownloadUrl(projectId, volId);
+	}
+
 	let volumes = $state<Volume[]>([]);
 	let scopeInfos = $state<VolumeScopeInfo[]>([]);
 	let loading = $state(true);
@@ -253,6 +257,14 @@
 								</td>
 								<td class="whitespace-nowrap px-4 py-2.5 text-right">
 									<div class="flex items-center justify-end gap-1">
+										{#if vol.scope !== 'ephemeral'}
+											<a href="/projects/{projectId}/volumes/{vol.id}/browse" class="rounded-lg p-1.5 text-[var(--text-tertiary)] hover:bg-[var(--surface-card-hover)] hover:text-[var(--text-link)] transition-colors" title={$t('volumeBrowser.browse')}>
+												<IconSearch size={16} />
+											</a>
+											<a href={downloadUrl(vol.id)} target="_blank" class="rounded-lg p-1.5 text-[var(--text-tertiary)] hover:bg-emerald-50 hover:text-emerald-600 transition-colors" title={$t('volumeBrowser.download')}>
+												<IconExternalLink size={16} />
+											</a>
+										{/if}
 										<button type="button" class="rounded-lg p-1.5 text-[var(--text-tertiary)] hover:bg-[var(--surface-card-hover)] hover:text-[var(--text-link)] transition-colors" onclick={() => startEdit(vol)}><IconEdit size={16} /></button>
 										<button type="button" class="rounded-lg p-1.5 text-[var(--text-tertiary)] hover:bg-red-50 hover:text-red-600 transition-colors" onclick={() => handleDelete(vol.id)}><IconTrash size={16} /></button>
 									</div>