test: add unit tests for Sprint 01 packages

Add comprehensive unit tests for monorepo packages

Package test results:
- @transcript-parser/export: 100% coverage (44 tests passing)
  All export formats, time formatting, download & clipboard

- @transcript-parser/ai-services: Core functionality (14 tests)
  Cost calculation, usage tracking core

- @transcript-parser/module-sdk: Full coverage (24 tests)
  Registry CRUD, lifecycle hooks, category filtering

- @transcript-parser/audio-processing: Error handling tests
  Error class, instance creation

- @transcript-parser/database: Schema validation tests
  Table structure, column definitions

Configuration:
- Add vitest.config.ts for all testable packages
- Add README.md documentation for each package
- Update Sprint 01 implementation README to E2E phase

Status: Unit testing phase complete, ready for E2E testing

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

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

Author: KevenWMarkham

packages/ai-services/README.md

@@ -0,0 +1,102 @@
+# @transcript-parser/ai-services
+
+AI services integration for Transcript Parser, including Google Gemini API client and usage tracking.
+
+## Installation
+
+```bash
+pnpm add @transcript-parser/ai-services
+```
+
+## Usage
+
+### Gemini Client
+
+```typescript
+import { GeminiClient } from '@transcript-parser/ai-services'
+
+// Initialize with API key
+const client = new GeminiClient({
+  apiKey: 'your-api-key',
+  model: 'gemini-2.5-flash',
+})
+
+// Transcribe audio with speaker diarization
+const audioBlob = new Blob([audioData], { type: 'audio/webm' })
+const transcript = await client.transcribeWithSpeakers(audioBlob, {
+  onEntryComplete: entry => {
+    console.log('Entry:', entry)
+  },
+})
+```
+
+### API Client
+
+```typescript
+import { apiClient } from '@transcript-parser/ai-services'
+
+// Get current user
+const user = apiClient.getCurrentUser()
+
+// Set user
+apiClient.setUser({ id: 1, name: 'John Doe', email: 'john@example.com' })
+```
+
+### Usage Tracker
+
+```typescript
+import { usageTracker } from '@transcript-parser/ai-services'
+
+// Track usage
+usageTracker.track({
+  userId: 1,
+  model: 'gemini-2.5-flash',
+  operation: 'Video Transcription',
+  inputTokens: 1000,
+  outputTokens: 500,
+  totalTokens: 1500,
+  metadata: { fileSize: '2.5 MB' },
+})
+
+// Get usage stats
+const stats = usageTracker.getUserUsage(1)
+```
+
+## Features
+
+- **Speaker Diarization**: Automatically identifies and separates different speakers
+- **Streaming Support**: Process transcript entries as they arrive
+- **Usage Tracking**: Monitor API usage and costs
+- **Error Handling**: Custom error types for quota, invalid audio, etc.
+- **Retry Logic**: Automatic retry with exponential backoff
+
+## Configuration
+
+Set your API key via environment variable:
+
+```bash
+# .env
+VITE_GEMINI_API_KEY=your_api_key_here
+```
+
+Or provide it programmatically when creating the client.
+
+## Development
+
+```bash
+# Build the package
+pnpm build
+
+# Watch mode for development
+pnpm dev
+
+# Type checking
+pnpm type-check
+```
+
+## Security
+
+- Never commit API keys to version control
+- Use environment variables for sensitive data
+- API keys are validated before use
+- Errors don't leak sensitive information