feat(ext): org collection facet + collection filter in the vault sidebar

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W3b8DA2mXmLWkd4zDbHXHg

extension/src/vault/__tests__/collection-facet.test.ts

@@ -15,9 +15,10 @@ vi.mock('../../shared/state', () => ({
 }));
 
 import { renderCollectionFacet } from '../vault-sidebar';
-import { getState } from '../../shared/state';
+import { getState, setState } from '../../shared/state';
 
 const mockGetState = getState as ReturnType<typeof vi.fn>;
+const mockSetState = setState as ReturnType<typeof vi.fn>;
 
 describe('vault collection facet (org context)', () => {
   beforeEach(() => {
@@ -38,4 +39,31 @@ describe('vault collection facet (org context)', () => {
 
     expect(el.textContent).toContain('Production Infra');
   });
+
+  it('clicking a collection row calls setState with the collection filter', () => {
+    mockGetState.mockReturnValue({
+      orgContext: 'org-1',
+      orgCollections: [{ slug: 'prod-infra', display_name: 'Production Infra' }],
+      collectionFilter: undefined,
+    });
+    const el = document.getElementById('facet')!;
+    renderCollectionFacet(el);
+
+    const btn = el.querySelector<HTMLButtonElement>('[data-slug="prod-infra"]')!;
+    expect(btn).not.toBeNull();
+    btn.click();
+
+    expect(mockSetState).toHaveBeenCalledWith({ collectionFilter: 'prod-infra' });
+  });
+
+  it('renders nothing in personal context', () => {
+    mockGetState.mockReturnValue({
+      orgContext: 'personal',
+      orgCollections: [],
+    });
+    const el = document.getElementById('facet')!;
+    renderCollectionFacet(el);
+
+    expect(el.innerHTML).toBe('');
+  });
 });