feat: pure tag-ranked art library search

src/art/search.js

@@ -0,0 +1,15 @@
+export function searchArt(manifest, query) {
+  const terms = String(query ?? '').toLowerCase().split(/\s+/).filter(Boolean);
+  if (terms.length === 0) return [...manifest];
+
+  const scored = manifest.map((asset, index) => {
+    const hay = [asset.label, ...(asset.tags || [])].join(' ').toLowerCase();
+    const score = terms.reduce((s, term) => s + (hay.includes(term) ? 1 : 0), 0);
+    return { asset, index, score };
+  });
+
+  return scored
+    .filter((r) => r.score > 0)
+    .sort((a, b) => b.score - a.score || a.index - b.index)
+    .map((r) => r.asset);
+}

tests/art/search.test.js

@@ -0,0 +1,30 @@
+import { describe, it, expect } from 'vitest';
+import { searchArt } from '../../src/art/search.js';
+
+const M = [
+  { id: 'a', src: 'a.png', label: 'Detective in alley', tags: ['detective', 'alley', 'rain'] },
+  { id: 'b', src: 'b.png', label: 'Neon street', tags: ['street', 'neon', 'rain'] },
+  { id: 'c', src: 'c.png', label: 'Worn portrait', tags: ['portrait', 'face'] },
+];
+
+describe('searchArt', () => {
+  it('returns the whole manifest for a blank query, in order', () => {
+    expect(searchArt(M, '').map((x) => x.id)).toEqual(['a', 'b', 'c']);
+    expect(searchArt(M, '   ').map((x) => x.id)).toEqual(['a', 'b', 'c']);
+  });
+
+  it('ranks by number of matched terms', () => {
+    // "rain alley" -> a matches both (2), b matches rain (1), c matches none
+    expect(searchArt(M, 'rain alley').map((x) => x.id)).toEqual(['a', 'b']);
+  });
+
+  it('matches substrings in tags or label, case-insensitive', () => {
+    expect(searchArt(M, 'DETECT').map((x) => x.id)).toEqual(['a']);
+    expect(searchArt(M, 'portrait').map((x) => x.id)).toEqual(['c']);
+  });
+
+  it('breaks rank ties by original manifest order', () => {
+    // "rain" -> a and b both match once; a comes first in manifest
+    expect(searchArt(M, 'rain').map((x) => x.id)).toEqual(['a', 'b']);
+  });
+});