Initial commit: Brachnha Insight project setup

- Next.js 14+ with App Router and TypeScript
- Tailwind CSS and ShadCN UI styling
- Zustand state management
- Dexie.js for IndexedDB (local-first data)
- Auth.js v5 for authentication
- BMAD framework integration

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

tests/unit/services/secure-storage.test.ts

@@ -0,0 +1,52 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { SecureStorage } from '../../../src/services/secure-storage'; // Implementation doesn't exist yet
+
+describe('SecureStorage Service', () => {
+    const TEST_KEY = 'test_api_key_123';
+    const STORAGE_KEY = 'llm_provider_config';
+
+    beforeEach(() => {
+        localStorage.clear();
+    });
+
+    afterEach(() => {
+        localStorage.clear();
+    });
+
+    it('should save API key with basic encoding (not plain text)', () => {
+        SecureStorage.saveKey(TEST_KEY);
+
+        // Direct access to localStorage to verify obfuscation
+        const storedValue = localStorage.getItem(STORAGE_KEY);
+        expect(storedValue).toBeDefined();
+        expect(storedValue).not.toBe(TEST_KEY); // Should NOT be plain text
+        expect(storedValue).not.toContain(TEST_KEY); // Should not contain the key
+    });
+
+    it('should retrieve the original API key correctly', () => {
+        SecureStorage.saveKey(TEST_KEY);
+
+        const retrievedKey = SecureStorage.getKey();
+        expect(retrievedKey).toBe(TEST_KEY);
+    });
+
+    it('should return null if no key is stored', () => {
+        const retrievedKey = SecureStorage.getKey();
+        expect(retrievedKey).toBeNull();
+    });
+
+    it('should overwrite existing key when saving new one', () => {
+        SecureStorage.saveKey('old_key');
+        SecureStorage.saveKey('new_key');
+
+        expect(SecureStorage.getKey()).toBe('new_key');
+    });
+
+    it('should clear key when requested', () => {
+        SecureStorage.saveKey(TEST_KEY);
+        SecureStorage.clearKey();
+
+        expect(SecureStorage.getKey()).toBeNull();
+        expect(localStorage.getItem(STORAGE_KEY)).toBeNull();
+    });
+});