refactor(search): extract ChipType to chip-types.ts; audit NL fixtures

Pre-implementation step for #743: ChipType union extracted from
InterpretationChipRow and +page.svelte into shared chip-types.ts;
resolvedTags/tagsApplied neutral defaults added to test fixtures.

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

frontend/e2e/nl-search.spec.ts

@@ -13,8 +13,10 @@ const interpretation = {
 	dateFrom: '1914-01-01',
 	dateTo: '1918-12-31',
 	keywords: ['krieg'],
+	resolvedTags: [{ id: '33333333-3333-3333-3333-333333333333', name: 'Weltkrieg', color: 'sage' }],
 	rawQuery: 'Was hat Walter an Emma im Krieg geschrieben?',
-	keywordsApplied: true
+	keywordsApplied: true,
+	tagsApplied: true
 };
 
 const nlResponse = {

frontend/src/routes/documents/+page.svelte

@@ -10,6 +10,7 @@ import BulkSelectionBar from '$lib/document/BulkSelectionBar.svelte';
 import TimelineDensityFilter from '$lib/document/TimelineDensityFilter.svelte';
 import SmartSearchStatus from '../search/SmartSearchStatus.svelte';
 import InterpretationChipRow from '../search/InterpretationChipRow.svelte';
+import type { ChipType } from '../search/chip-types.js';
 import DisambiguationPicker from '../search/DisambiguationPicker.svelte';
 import { bulkSelectionStore } from '$lib/document/bulkSelection.svelte';
 import { getErrorMessage, parseBackendError } from '$lib/shared/errors';
@@ -269,8 +270,6 @@ function paramsFromInterpretation(interp: NlQueryInterpretation) {
 	};
 }
 
-type ChipType = 'sender' | 'directional' | 'date' | 'keyword';
-
 function removeChip(type: ChipType, value?: string) {
 	if (!nlInterpretation) return;
 	const p = paramsFromInterpretation(nlInterpretation);

frontend/src/routes/search/InterpretationChipRow.svelte

@@ -3,8 +3,9 @@ import { SvelteSet } from 'svelte/reactivity';
 import { m } from '$lib/paraglide/messages.js';
 import type { components } from '$lib/generated/api';
 
+import type { ChipType } from './chip-types.js';
+
 type NlQueryInterpretation = components['schemas']['NlQueryInterpretation'];
-type ChipType = 'sender' | 'directional' | 'date' | 'keyword';
 
 let {
 	interpretation,

frontend/src/routes/search/InterpretationChipRow.svelte.spec.ts

@@ -17,8 +17,10 @@ const makeInterpretation = (
 	resolvedPersons: [],
 	ambiguousPersons: [],
 	keywords: [],
+	resolvedTags: [],
 	rawQuery: 'test',
 	keywordsApplied: true,
+	tagsApplied: false,
 	...overrides
 });
 

frontend/src/routes/search/chip-types.ts

@@ -0,0 +1 @@
+export type ChipType = 'sender' | 'directional' | 'date' | 'keyword' | 'theme';