feat: add download toast, e2e permission tests, and update favicons

- Add download toast component with progress indicator and auto-dismiss
- Add download store for managing file download state
- Add e2e tests for permission prompts (allow/deny flows)
- Add global setup for e2e tests with isolated daemon instance
- Update favicon assets with new design
- Refactor agent-stream-view to use shared tool-call-details component
- Simplify file-explorer-pane component
- Clean up unused screenshots and PRODUCTION.md

🤖 Generated with [Claude Code](https://claude.com/claude-code)

packages/app/playwright.config.ts

@@ -4,6 +4,7 @@ const baseURL = process.env.E2E_BASE_URL ?? 'http://localhost:8081';
 
 export default defineConfig({
   testDir: './e2e',
+  globalSetup: './e2e/global-setup.ts',
   timeout: 60_000,
   expect: {
     timeout: 10_000,