feat(devices): pure icon resolver + relativeTime helpers

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/views/icon_util.test.js

@@ -0,0 +1,29 @@
+import { describe, it, expect } from 'vitest';
+import { resolveIcon, relativeTime, autoDefaultIcon } from '../../public/views/icon_util.js';
+
+describe('autoDefaultIcon', () => {
+  it('maps groups to bundled icons', () => {
+    expect(autoDefaultIcon('Network')).toBe('set:devices:router');
+    expect(autoDefaultIcon('Entertainment')).toBe('set:devices:tv');
+    expect(autoDefaultIcon('Smart Home')).toBe('set:devices:plug');
+    expect(autoDefaultIcon('Personal')).toBe('set:devices:phone');
+    expect(autoDefaultIcon('whatever')).toBe('set:devices:unknown');
+  });
+});
+describe('resolveIcon', () => {
+  it('resolves set + brand refs', () => {
+    expect(resolveIcon('set:devices:router')).toBe('/api/icon-sets/devices/router.svg');
+    expect(resolveIcon('set:mine:nas')).toBe('/api/icon-sets/mine/nas.svg');
+    expect(resolveIcon('brand:apple')).toBe('/api/icons/apple.png');
+  });
+  it('returns null for junk', () => { expect(resolveIcon('nope')).toBeNull(); });
+});
+describe('relativeTime', () => {
+  const base = Date.parse('2026-06-09T12:00:00Z');
+  it('formats buckets', () => {
+    expect(relativeTime('2026-06-09T11:59:30Z', base)).toBe('just now');
+    expect(relativeTime('2026-06-09T11:40:00Z', base)).toBe('20m ago');
+    expect(relativeTime('2026-06-09T09:00:00Z', base)).toBe('3h ago');
+    expect(relativeTime('2026-06-06T12:00:00Z', base)).toBe('3d ago');
+  });
+});