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/DescriptionSection.svelte.spec.ts

@@ -0,0 +1,57 @@
+import { afterEach, describe, expect, it } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import DescriptionSection from './DescriptionSection.svelte';
+
+afterEach(() => cleanup());
+
+describe('DescriptionSection — onMount seeding (Felix B1/B2 fix regression fence)', () => {
+	it('pre-fills the title input from initialTitle when currentTitle is empty', async () => {
+		render(DescriptionSection, { initialTitle: 'Brief an Anna' });
+		const titleInput = document.querySelector('input#title') as HTMLInputElement;
+		expect(titleInput).not.toBeNull();
+		expect(titleInput.value).toBe('Brief an Anna');
+	});
+
+	it('does not stomp a parent-bound currentTitle that is already non-empty', async () => {
+		render(DescriptionSection, {
+			currentTitle: 'Parent Title',
+			initialTitle: 'Should Not Win'
+		});
+		const titleInput = document.querySelector('input#title') as HTMLInputElement;
+		expect(titleInput.value).toBe('Parent Title');
+	});
+
+	it('always renders archiveBox + archiveFolder fields regardless of editMode', async () => {
+		render(DescriptionSection, { editMode: false });
+		expect(document.querySelector('[data-testid="description-archive-box"]')).not.toBeNull();
+		expect(document.querySelector('[data-testid="description-archive-folder"]')).not.toBeNull();
+	});
+
+	it('renders the editMode-only archiveBox + archiveFolder fields when editMode=true', async () => {
+		render(DescriptionSection, { editMode: true, hideTitle: true });
+		expect(document.querySelector('[data-testid="description-archive-box"]')).not.toBeNull();
+		expect(document.querySelector('[data-testid="description-archive-folder"]')).not.toBeNull();
+	});
+
+	it('pre-fills archiveBox from initialArchiveBox when archiveBox is empty', async () => {
+		render(DescriptionSection, { initialArchiveBox: 'K-03', hideTitle: true });
+		const input = document.querySelector('input#archiveBox') as HTMLInputElement;
+		expect(input.value).toBe('K-03');
+	});
+
+	it('pre-fills archiveFolder from initialArchiveFolder when archiveFolder is empty', async () => {
+		render(DescriptionSection, { initialArchiveFolder: 'Mappe B', hideTitle: true });
+		const input = document.querySelector('input#archiveFolder') as HTMLInputElement;
+		expect(input.value).toBe('Mappe B');
+	});
+
+	it('does not stomp a parent-bound archiveBox that is already non-empty', async () => {
+		render(DescriptionSection, {
+			archiveBox: 'Parent Value',
+			initialArchiveBox: 'Should Not Win',
+			hideTitle: true
+		});
+		const input = document.querySelector('input#archiveBox') as HTMLInputElement;
+		expect(input.value).toBe('Parent Value');
+	});
+});