feat(ui): redesign voice cockpit with clinical companion drawer, Svelte 5 migration, and Gemini 3.8 voice

- Re-architect VoiceSession into full-bleed studio cockpit with overlay slide-over companion drawer
- Eliminate width squishing defect on LiveInsightPanel and add native dark/light theme support
- Integrate authentic Google Gemini 3.8 Flash TTS with Fenrir persona and fallback audio pipeline
- Implement comprehensive Playwright E2E visual regression suite across Desktop, iPad, and iPhone (21 tests, 45 snapshots)
- Migrate core application to Svelte 5 runes (, , ) with reactive stores
- Maintain .NET 8 Azure Functions serverless endpoints and clean build hygiene

playwright.config.ts

@@ -0,0 +1,55 @@
+import { defineConfig, devices } from '@playwright/test';
+
+export default defineConfig({
+  testDir: './tests/e2e',
+  timeout: 30 * 1000,
+  expect: {
+    timeout: 5000
+  },
+  fullyParallel: false,
+  forbidOnly: !!process.env.CI,
+  retries: process.env.CI ? 2 : 0,
+  workers: 1,
+  reporter: [
+    ['list'],
+    ['html', { outputFolder: 'playwright-report', open: 'never' }]
+  ],
+  use: {
+    baseURL: 'http://localhost:3000',
+    trace: 'on-first-retry',
+    video: 'off',
+    screenshot: 'off'
+  },
+  projects: [
+    {
+      name: 'desktop-chrome',
+      use: {
+        ...devices['Desktop Chrome'],
+        viewport: { width: 1440, height: 900 }
+      }
+    },
+    {
+      name: 'ipad-portrait',
+      use: {
+        viewport: { width: 834, height: 1194 },
+        deviceScaleFactor: 2,
+        isMobile: true,
+        hasTouch: true,
+        userAgent:
+          'Mozilla/5.0 (iPad; CPU OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1'
+      }
+    },
+    {
+      name: 'mobile-iphone',
+      use: {
+        ...devices['iPhone 14']
+      }
+    }
+  ],
+  webServer: {
+    command: 'npm run dev -- --port 3000',
+    url: 'http://localhost:3000',
+    reuseExistingServer: !process.env.CI,
+    timeout: 120 * 1000
+  }
+});