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

test/apiConfig.test.ts

@@ -0,0 +1,65 @@
+import { describe, test, expect } from 'vitest';
+import { 
+  DEFAULT_OPENROUTER_MODEL, 
+  DEFAULT_SUPERVISOR_MODEL, 
+  getOpenRouterApiKey, 
+  hasOpenRouterApiKey,
+  getGeminiApiKey,
+  hasGeminiApiKey
+} from '../services/apiConfig';
+
+describe('API Configuration & Model Defaults', () => {
+  test('should default to latest Google Gemini 3.8 Flash model', () => {
+    expect(DEFAULT_OPENROUTER_MODEL).toBe('google/gemini-3.8-flash');
+    expect(DEFAULT_SUPERVISOR_MODEL).toBe('google/gemini-3.8-flash');
+  });
+
+  test('should return trimmed explicit custom API key when provided', () => {
+    const key = getOpenRouterApiKey('  sk-or-v1-custom-key-12345  ');
+    expect(key).toBe('sk-or-v1-custom-key-12345');
+  });
+
+  test('should fallback to environment variable when no argument or stored setting exists', () => {
+    const originalEnv = process.env.OPENROUTER_API_KEY;
+    try {
+      process.env.OPENROUTER_API_KEY = 'sk-or-v1-env-fallback-key';
+      const key = getOpenRouterApiKey();
+      expect(key).toBe('sk-or-v1-env-fallback-key');
+      expect(hasOpenRouterApiKey()).toBe(true);
+    } finally {
+      if (originalEnv !== undefined) {
+        process.env.OPENROUTER_API_KEY = originalEnv;
+      } else {
+        delete process.env.OPENROUTER_API_KEY;
+      }
+    }
+  });
+
+  test('should return empty string when no keys are configured', () => {
+    const originalEnv = process.env.OPENROUTER_API_KEY;
+    try {
+      process.env.OPENROUTER_API_KEY = '';
+      const key = getOpenRouterApiKey('');
+      expect(key).toBe('');
+    } finally {
+      if (originalEnv !== undefined) {
+        process.env.OPENROUTER_API_KEY = originalEnv;
+      }
+    }
+  });
+
+  test('should resolve Google Gemini API Key from environment or explicit argument', () => {
+    expect(getGeminiApiKey('AIzaSyCustomKey')).toBe('AIzaSyCustomKey');
+    expect(hasGeminiApiKey()).toBe(true);
+
+    const originalEnv = process.env.GEMINI_API_KEY;
+    try {
+      process.env.GEMINI_API_KEY = 'AIzaSyFallbackKey';
+      expect(getGeminiApiKey()).toBe('AIzaSyFallbackKey');
+    } finally {
+      if (originalEnv !== undefined) {
+        process.env.GEMINI_API_KEY = originalEnv;
+      }
+    }
+  });
+});