feat(ui): add TranscriptionReadView for flowing prose display

Renders transcription blocks as readable text with [unleserlich]/[...]
markers styled as italic muted text. Supports click-to-sync and
flash highlight for scroll-sync feedback.

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

frontend/src/lib/components/TranscriptionReadView.svelte

@@ -0,0 +1,51 @@
+<script lang="ts">
+import type { TranscriptionBlockData } from '$lib/types';
+import { splitByMarkers } from '$lib/utils/transcriptionMarkers';
+
+interface Props {
+	blocks: TranscriptionBlockData[];
+	onParagraphClick: (annotationId: string) => void;
+	highlightBlockId?: string | null;
+}
+
+let { blocks, onParagraphClick, highlightBlockId = null }: Props = $props();
+
+let sorted = $derived([...blocks].sort((a, b) => a.sortOrder - b.sortOrder));
+</script>
+
+<article class="px-6 py-8">
+	{#each sorted as block (block.id)}
+		<div
+			class="-mx-2 mb-6 cursor-pointer rounded-sm px-2 py-1 font-serif text-[16px] leading-[1.85] text-ink transition-colors hover:bg-[rgba(0,199,177,0.06)]"
+			class:flash-highlight={highlightBlockId === block.id}
+			data-block-id={block.id}
+			onclick={() => onParagraphClick(block.annotationId)}
+			role="button"
+			tabindex="0"
+			onkeydown={(e) => { if (e.key === 'Enter' || e.key === ' ') onParagraphClick(block.annotationId); }}
+		>
+			{#each splitByMarkers(block.text) as segment, i (i)}
+				{#if segment.type === 'marker'}
+					<em data-marker class="text-ink-2 italic">{segment.text}</em>
+				{:else}
+					{segment.text}
+				{/if}
+			{/each}
+		</div>
+	{/each}
+</article>
+
+<style>
+@keyframes flash {
+	0% {
+		background-color: rgba(0, 199, 177, 0.18);
+	}
+	100% {
+		background-color: transparent;
+	}
+}
+
+.flash-highlight {
+	animation: flash 1.2s ease-out;
+}
+</style>

frontend/src/lib/components/TranscriptionReadView.svelte.test.ts

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+import { describe, it, expect, vi } from 'vitest';
+import { render } from 'vitest-browser-svelte';
+import { page } from 'vitest/browser';
+import TranscriptionReadView from './TranscriptionReadView.svelte';
+import type { TranscriptionBlockData } from '$lib/types';
+
+const blocks: TranscriptionBlockData[] = [
+	{
+		id: 'b1',
+		annotationId: 'ann-1',
+		documentId: 'doc-1',
+		text: 'First paragraph text.',
+		label: null,
+		sortOrder: 1,
+		version: 1
+	},
+	{
+		id: 'b2',
+		annotationId: 'ann-2',
+		documentId: 'doc-1',
+		text: 'Second paragraph text.',
+		label: null,
+		sortOrder: 2,
+		version: 1
+	}
+];
+
+describe('TranscriptionReadView', () => {
+	it('should render one paragraph per block', async () => {
+		render(TranscriptionReadView, {
+			blocks,
+			onParagraphClick: () => {}
+		});
+
+		await expect.element(page.getByText('First paragraph text.')).toBeInTheDocument();
+		await expect.element(page.getByText('Second paragraph text.')).toBeInTheDocument();
+
+		const paragraphs = document.querySelectorAll('[data-block-id]');
+		expect(paragraphs.length).toBe(2);
+	});
+
+	it('should render [unleserlich] as italic muted text', async () => {
+		render(TranscriptionReadView, {
+			blocks: [
+				{
+					id: 'b1',
+					annotationId: 'ann-1',
+					documentId: 'doc-1',
+					text: 'Text before [unleserlich] text after',
+					label: null,
+					sortOrder: 1,
+					version: 1
+				}
+			],
+			onParagraphClick: () => {}
+		});
+
+		const marker = document.querySelector('[data-marker]');
+		expect(marker).not.toBeNull();
+		expect(marker!.textContent).toBe('[unleserlich]');
+		expect(marker!.tagName.toLowerCase()).toBe('em');
+	});
+
+	it('should render [...] as italic muted text', async () => {
+		render(TranscriptionReadView, {
+			blocks: [
+				{
+					id: 'b1',
+					annotationId: 'ann-1',
+					documentId: 'doc-1',
+					text: 'Some [...] text',
+					label: null,
+					sortOrder: 1,
+					version: 1
+				}
+			],
+			onParagraphClick: () => {}
+		});
+
+		const marker = document.querySelector('[data-marker]');
+		expect(marker).not.toBeNull();
+		expect(marker!.textContent).toBe('[...]');
+	});
+
+	it('should call onParagraphClick with annotationId when paragraph is clicked', async () => {
+		const onParagraphClick = vi.fn();
+		render(TranscriptionReadView, {
+			blocks,
+			onParagraphClick
+		});
+
+		const paragraph = document.querySelector('[data-block-id="b1"]')!;
+		paragraph.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+		expect(onParagraphClick).toHaveBeenCalledWith('ann-1');
+	});
+
+	it('should render blocks sorted by sortOrder', async () => {
+		render(TranscriptionReadView, {
+			blocks: [
+				{ ...blocks[1], sortOrder: 1 },
+				{ ...blocks[0], sortOrder: 2 }
+			],
+			onParagraphClick: () => {}
+		});
+
+		const paragraphs = document.querySelectorAll('[data-block-id]');
+		expect(paragraphs[0].getAttribute('data-block-id')).toBe('b2');
+		expect(paragraphs[1].getAttribute('data-block-id')).toBe('b1');
+	});
+
+	it('should render empty state when no blocks', async () => {
+		render(TranscriptionReadView, {
+			blocks: [],
+			onParagraphClick: () => {}
+		});
+
+		const paragraphs = document.querySelectorAll('[data-block-id]');
+		expect(paragraphs.length).toBe(0);
+	});
+});