feat(search): add onTextInput callback to TagInput for live tag filter

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

frontend/src/lib/components/TagInput.svelte

@@ -6,9 +6,10 @@ import { clickOutside } from '$lib/actions/clickOutside';
 interface Props {
 	tags?: string[];
 	allowCreation?: boolean;
+	onTextInput?: (text: string) => void;
 }
 
-let { tags = $bindable([]), allowCreation = true }: Props = $props();
+let { tags = $bindable([]), allowCreation = true, onTextInput }: Props = $props();
 
 let inputVal = $state('');
 let suggestions: string[] = $state([]);
@@ -101,7 +102,7 @@ function handleKeydown(e: KeyboardEvent) {
 			<input
 				type="text"
 				bind:value={inputVal}
-				oninput={() => fetchSuggestions(inputVal)}
+				oninput={() => { fetchSuggestions(inputVal); onTextInput?.(inputVal); }}
 				onkeydown={handleKeydown}
 				onfocus={() => fetchSuggestions(inputVal)}
 				placeholder={tags.length === 0

frontend/src/lib/components/TagInput.svelte.spec.ts

@@ -208,3 +208,24 @@ describe('TagInput – autocomplete', () => {
 		await expect.element(page.getByRole('option', { name: 'Familie' })).not.toBeInTheDocument();
 	});
 });
+
+// ─── onTextInput callback ──────────────────────────────────────────────────────
+
+describe('TagInput – onTextInput callback', () => {
+	it('calls onTextInput with the current value on every input event', async () => {
+		mockFetchEmpty();
+		const onTextInput = vi.fn();
+		render(TagInput, { tags: [], allowCreation: false, onTextInput });
+		const input = page.getByRole('textbox');
+		await input.fill('fa');
+		await expect.poll(() => onTextInput.mock.calls.length).toBeGreaterThan(0);
+		expect(onTextInput).toHaveBeenCalledWith('fa');
+	});
+
+	it('does not throw when onTextInput is not provided', async () => {
+		mockFetchEmpty();
+		render(TagInput, { tags: [], allowCreation: false });
+		const input = page.getByRole('textbox');
+		await expect(input.fill('fa')).resolves.not.toThrow();
+	});
+});