refactor: move document domain core to lib/document/

Moves ~25 components, utils (search, filename, groupDocuments,
documentStatusLabel, validateFile), bulkSelection store, and
TranscriptionSection sub-component. Fixes broken relative imports.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/document/UploadSaveBar.svelte

@@ -0,0 +1,69 @@
+<script lang="ts">
+import { m } from '$lib/paraglide/messages.js';
+
+let {
+	fileCount,
+	chunkProgress,
+	onSave,
+	onDiscard,
+	disabled = false,
+	editMode = false
+}: {
+	fileCount: number;
+	chunkProgress?: { done: number; total: number };
+	onSave: () => void;
+	onDiscard: () => void | Promise<void>;
+	disabled?: boolean;
+	editMode?: boolean;
+} = $props();
+
+const saveCta = $derived.by(() => {
+	if (editMode) return m.bulk_edit_save_button();
+	return fileCount === 1 ? m.bulk_save_cta_one() : m.bulk_save_cta({ count: fileCount });
+});
+</script>
+
+<div class="shrink-0 border-t border-line bg-surface px-4 py-3">
+	{#if chunkProgress}
+		<progress
+			value={chunkProgress.done}
+			max={chunkProgress.total}
+			aria-valuenow={chunkProgress.done}
+			aria-valuemin={0}
+			aria-valuemax={chunkProgress.total}
+			aria-label={editMode
+				? m.bulk_edit_save_progress({ done: chunkProgress.done, total: chunkProgress.total })
+				: m.bulk_upload_progress({ done: chunkProgress.done, total: chunkProgress.total })}
+			class="[&::-webkit-progress-bar]:bg-brand-sand mb-2 h-1 w-full rounded-full [&::-webkit-progress-bar]:rounded-full [&::-webkit-progress-value]:rounded-full [&::-webkit-progress-value]:bg-accent"
+		></progress>
+		{#if editMode && chunkProgress.total > 1}
+			<!-- Visible progress text for sighted users on multi-chunk PATCH
+				 (Elicit S3 — the unitless bar isn't enough for a 30-second op). -->
+			<p
+				class="mb-2 font-sans text-xs text-ink-2"
+				aria-live="polite"
+				data-testid="bulk-edit-chunk-progress-text"
+			>
+				{m.bulk_edit_save_progress({ done: chunkProgress.done, total: chunkProgress.total })}
+			</p>
+		{/if}
+	{/if}
+	<div class="flex items-center justify-between gap-3">
+		<button
+			type="button"
+			onclick={onDiscard}
+			class="flex min-h-[44px] items-center px-2 text-sm text-red-600/70 hover:text-red-700"
+		>
+			{m.bulk_discard_all()}
+		</button>
+		<button
+			type="button"
+			data-testid="bulk-save-btn"
+			disabled={fileCount === 0 || disabled}
+			onclick={onSave}
+			class="min-h-[44px] rounded-sm bg-primary px-6 text-sm font-bold tracking-widest text-primary-fg uppercase transition-opacity hover:opacity-90 disabled:opacity-40"
+		>
+			{saveCta}
+		</button>
+	</div>
+</div>