feat: Improve UI layout and navigation

- Increase logo size (48x48 desktop, 56x56 mobile) for better visibility
- Add logo as favicon
- Add logo to mobile header
- Move user menu to navigation bars (sidebar on desktop, bottom bar on mobile)
- Fix desktop chat layout - container structure prevents voice controls cutoff
- Fix mobile bottom bar - use icon-only ActionIcons instead of truncated text buttons
- Hide Create Node/New Conversation buttons on mobile to save header space
- Make fixed header and voice controls work properly with containers

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

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

playwright.config.ts

@@ -0,0 +1,40 @@
+import { defineConfig, devices } from '@playwright/test';
+
+export default defineConfig({
+  testDir: './tests',
+  fullyParallel: true,
+  forbidOnly: !!process.env.CI,
+  retries: process.env.CI ? 2 : 0,
+  workers: process.env.CI ? 1 : undefined,
+  reporter: 'html',
+  use: {
+    baseURL: 'http://localhost:3000',
+    trace: 'on-first-retry',
+  },
+
+  projects: [
+    // Setup project
+    {
+      name: 'setup',
+      testMatch: /.*\.setup\.ts/,
+    },
+
+    // Chromium tests using authenticated state
+    {
+      name: 'chromium',
+      use: {
+        ...devices['Desktop Chrome'],
+        // Use the saved authenticated state
+        storageState: '.playwright/.auth/user.json',
+      },
+      dependencies: ['setup'],
+    },
+  ],
+
+  // Run dev server before tests
+  webServer: {
+    command: 'pnpm dev',
+    url: 'http://localhost:3000',
+    reuseExistingServer: !process.env.CI,
+  },
+});