refactor: move lib-root files to lib/shared/ and finalize domain structure

- Move api.server.ts, errors.ts, types.ts, utils.ts, relativeTime.ts to lib/shared/
- Move person relationship components to lib/person/relationship/
- Move Stammbaum components to lib/person/genealogy/
- Move HelpPopover to lib/shared/primitives/
- Update all import paths across routes, specs, and lib files
- Update vi.mock() paths in server-project test files
- Remove now-empty legacy directories (components/, hooks/, server/, etc.)
- Update vite.config.ts coverage include paths for new structure
- Update frontend/CLAUDE.md to reflect domain-based lib/ layout

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

frontend/src/lib/document/viewer/PdfViewer.svelte

@@ -3,9 +3,9 @@ import { onMount, setContext } from 'svelte';
 import { createPdfRenderer } from '$lib/document/viewer/usePdfRenderer.svelte';
 import PdfControls from './PdfControls.svelte';
 import AnnotationLayer from '$lib/document/annotation/AnnotationLayer.svelte';
-import type { Annotation } from '$lib/types';
+import type { Annotation } from '$lib/shared/types';
 import { m } from '$lib/paraglide/messages.js';
-import { parseBackendError, getErrorMessage } from '$lib/errors';
+import { parseBackendError, getErrorMessage } from '$lib/shared/errors';
 
 type DrawRect = { x: number; y: number; width: number; height: number; pageNumber: number };