refactor(person-mention): hoist LoadState + HoverData into shared types module

Markus flagged the LoadState export from PersonHoverCard.svelte as a
view-vs-orchestrator boundary smell — both files own the same shape, and a
third caller (admin previews, briefwechsel cards) would create a circular
import. Move the types into src/lib/types/personHoverCard.ts so the contract
is module-stable.

Also harden .prettierignore + eslint.config.js so a stray .svelte-kit.old/
backup directory (rotated by SvelteKit during dev) doesn't break the lint
hook — matches the existing .svelte-kit-backup/ convention.

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

frontend/.prettierignore

@@ -11,6 +11,7 @@ bun.lockb
 # Build artifacts
 /.svelte-kit/
 /.svelte-kit-backup/
+/.svelte-kit.old/
 
 # Generated files
 /.svelte-kit-backup/

frontend/eslint.config.js

@@ -12,7 +12,7 @@ const gitignorePath = fileURLToPath(new URL('./.gitignore', import.meta.url));
 
 export default defineConfig(
 	includeIgnoreFile(gitignorePath),
-	{ ignores: ['src/paraglide/**'] },
+	{ ignores: ['src/paraglide/**', '.svelte-kit.old/**'] },
 	js.configs.recommended,
 	...ts.configs.recommended,
 	...svelte.configs.recommended,

frontend/src/lib/components/PersonHoverCard.svelte

@@ -2,15 +2,10 @@
 import { m } from '$lib/paraglide/messages.js';
 import { formatLifeDateRange } from '$lib/utils/personLifeDates';
 import type { components } from '$lib/generated/api';
+import type { LoadState } from '$lib/types/personHoverCard';
 
-type Person = components['schemas']['Person'];
 type RelationshipDTO = components['schemas']['RelationshipDTO'];
 
-export type LoadState =
-	| { status: 'loading' }
-	| { status: 'error' }
-	| { status: 'loaded'; person: Person; relationships: RelationshipDTO[] };
-
 type Props = {
 	personId: string;
 	cardId: string;

frontend/src/lib/components/TranscriptionReadView.svelte

@@ -3,15 +3,14 @@ import type { TranscriptionBlockData } from '$lib/types';
 import type { components } from '$lib/generated/api';
 import { splitByMarkers } from '$lib/utils/transcriptionMarkers';
 import { renderTranscriptionBody } from '$lib/utils/mention';
-import PersonHoverCard, { type LoadState } from './PersonHoverCard.svelte';
+import PersonHoverCard from './PersonHoverCard.svelte';
+import type { HoverData, LoadState } from '$lib/types/personHoverCard';
 import { goto } from '$app/navigation';
 import { SvelteMap, SvelteSet } from 'svelte/reactivity';
 
 type Person = components['schemas']['Person'];
 type RelationshipDTO = components['schemas']['RelationshipDTO'];
 
-type HoverData = { person: Person; relationships: RelationshipDTO[] };
-
 interface Props {
 	blocks: TranscriptionBlockData[];
 	onParagraphClick: (annotationId: string) => void;

frontend/src/lib/types/personHoverCard.ts

@@ -0,0 +1,23 @@
+import type { components } from '$lib/generated/api';
+
+type Person = components['schemas']['Person'];
+type RelationshipDTO = components['schemas']['RelationshipDTO'];
+
+/**
+ * Data the PersonHoverCard needs to render its loaded state.
+ * Bundled here so the orchestrator (TranscriptionReadView) and the view
+ * (PersonHoverCard) share one canonical shape.
+ */
+export type HoverData = { person: Person; relationships: RelationshipDTO[] };
+
+/**
+ * The hover card's three visible states.
+ *
+ * `loading`  — initial fetch in flight; skeleton is shown
+ * `error`    — fetch failed (non-404, non-OK); generic error message + footer link
+ * `loaded`   — fetch succeeded; person + relationships available
+ */
+export type LoadState =
+	| { status: 'loading' }
+	| { status: 'error' }
+	| { status: 'loaded'; person: Person; relationships: RelationshipDTO[] };