feat(recipes): add FilterChipRow with effort filter chips

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

frontend/src/lib/recipes/FilterChipRow.svelte

@@ -0,0 +1,20 @@
+<script lang="ts">
+  let { activeFilter, onFilter }: { activeFilter: string; onFilter: (filter: string) => void } = $props();
+
+  const chips = ['Alle', 'Leicht', 'Mittel', 'Schwer'];
+</script>
+
+<div class="flex gap-[8px] overflow-x-auto px-[16px] py-[12px] scrollbar-none">
+  {#each chips as label (label)}
+    <button
+      type="button"
+      aria-pressed={activeFilter === label}
+      onclick={() => onFilter(label)}
+      class="font-sans text-[11px] font-medium px-[14px] py-[5px] rounded-[12px] border cursor-pointer focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-[var(--green-light)] {activeFilter === label
+        ? 'bg-[var(--green-tint)] text-[var(--green-dark)] border-[var(--green-light)]'
+        : 'bg-[var(--color-surface)] text-[var(--color-text-muted)] border-[var(--color-border)]'}"
+    >
+      {label}
+    </button>
+  {/each}
+</div>

frontend/src/lib/recipes/FilterChipRow.test.ts

@@ -0,0 +1,51 @@
+import { describe, it, expect, vi } from 'vitest';
+import { render, screen } from '@testing-library/svelte';
+import { userEvent } from '@testing-library/user-event';
+import FilterChipRow from './FilterChipRow.svelte';
+
+describe('FilterChipRow', () => {
+	it('renders all effort filter chips', () => {
+		render(FilterChipRow, { props: { activeFilter: 'Alle', onFilter: vi.fn() } });
+		expect(screen.getByRole('button', { name: 'Alle' })).toBeInTheDocument();
+		expect(screen.getByRole('button', { name: 'Leicht' })).toBeInTheDocument();
+		expect(screen.getByRole('button', { name: 'Mittel' })).toBeInTheDocument();
+		expect(screen.getByRole('button', { name: 'Schwer' })).toBeInTheDocument();
+	});
+
+	it('marks active chip with aria-pressed=true', () => {
+		render(FilterChipRow, { props: { activeFilter: 'Leicht', onFilter: vi.fn() } });
+		expect(screen.getByRole('button', { name: 'Leicht' })).toHaveAttribute('aria-pressed', 'true');
+		expect(screen.getByRole('button', { name: 'Alle' })).toHaveAttribute('aria-pressed', 'false');
+	});
+
+	it('marks inactive chips with aria-pressed=false', () => {
+		render(FilterChipRow, { props: { activeFilter: 'Alle', onFilter: vi.fn() } });
+		expect(screen.getByRole('button', { name: 'Leicht' })).toHaveAttribute('aria-pressed', 'false');
+		expect(screen.getByRole('button', { name: 'Mittel' })).toHaveAttribute('aria-pressed', 'false');
+		expect(screen.getByRole('button', { name: 'Schwer' })).toHaveAttribute('aria-pressed', 'false');
+	});
+
+	it('calls onFilter with the chip label when clicked', async () => {
+		const user = userEvent.setup();
+		const onFilter = vi.fn();
+		render(FilterChipRow, { props: { activeFilter: 'Alle', onFilter } });
+
+		await user.click(screen.getByRole('button', { name: 'Leicht' }));
+		expect(onFilter).toHaveBeenCalledWith('Leicht');
+	});
+
+	it('calls onFilter with Alle when reset chip clicked', async () => {
+		const user = userEvent.setup();
+		const onFilter = vi.fn();
+		render(FilterChipRow, { props: { activeFilter: 'Leicht', onFilter } });
+
+		await user.click(screen.getByRole('button', { name: 'Alle' }));
+		expect(onFilter).toHaveBeenCalledWith('Alle');
+	});
+
+	it('active chip has green-tint styling', () => {
+		render(FilterChipRow, { props: { activeFilter: 'Mittel', onFilter: vi.fn() } });
+		const btn = screen.getByRole('button', { name: 'Mittel' });
+		expect(btn.className).toContain('bg-[var(--green-tint)]');
+	});
+});