feat: Phase 6 - MCP + Webhooks + Worker + Polish

- MCP server: stateless JSON-RPC 2.0 with 18 tools (tasks, habits, projects, notes, domains, search, activity)
- Webhooks API: CRUD routes under /api/domains/[domainId]/webhooks/ with test endpoint and deliveries log
- Webhook delivery: HMAC-SHA256 signed POST with retry (exponential backoff, max 6)
- Worker rewrite: Drizzle ORM instead of PocketBase, polls jobs table, handles webhook_delivery, recurring_spawn, ai_dispatch
- Rate limiting: token bucket per IP/API key (100 req/min REST, 300 req/min MCP)
- Keyboard help overlay: ? opens Radix Dialog with search/filter, Esc closes
- AI @mention stub: @agent in command palette dispatches CustomEvent
- Mobile responsive: bottom nav, single-column kanban, day view calendar, 44px touch targets
- Accessibility: skip-to-content link, focus rings, aria-labels, color contrast
- E2E tests: mcp.spec.ts, webhooks.spec.ts, realtime.spec.ts added
- Schema: api_keys and webhook_deliveries tables with migration
- Removed old PocketBase-style database.ts from worker

e2e/realtime.spec.ts

@@ -0,0 +1,37 @@
+import { test, expect } from '@playwright/test';
+import { login } from './helpers/auth';
+
+test.describe('Realtime Updates', () => {
+  test('should connect to SSE endpoint', async ({ page }) => {
+    await login(page);
+
+    // Navigate to dashboard
+    await page.goto('/dashboard');
+    await expect(page.getByRole('heading', { name: /dashboard/i })).toBeVisible();
+
+    // The SSE connection is established automatically via the realtime hook
+    // Verify the page loaded without errors
+    const consoleMessages: string[] = [];
+    page.on('console', (msg) => {
+      if (msg.type() === 'error') {
+        consoleMessages.push(msg.text());
+      }
+    });
+
+    await page.waitForTimeout(2000);
+
+    // Check for SSE-related errors
+    const sseErrors = consoleMessages.filter(
+      (m) => m.includes('realtime') || m.includes('SSE') || m.includes('EventSource')
+    );
+    expect(sseErrors.length).toBe(0);
+  });
+
+  test('should have realtime API endpoint', async ({ page }) => {
+    const response = await page.request.get('/api/realtime');
+    // SSE endpoint should return 200 with text/event-stream content type
+    expect(response.status()).toBe(200);
+    const contentType = response.headers()['content-type'] || '';
+    expect(contentType).toContain('text/event-stream');
+  });
+});