Add full support for tracking and analyzing data by service in multi-tenant deployments.
## Features Added
- **Service Statistics Tracking**: Track nouns, verbs, and metadata counts per service
- **Service Activity Monitoring**: Track first/last activity timestamps and operation counts
- **New API Methods**:
- `listServices()`: List all services with their statistics and status
- `getServiceStatistics(service)`: Get detailed stats for a specific service
- Enhanced `getStatistics()` with service filtering and breakdown
- **Service Filtering**: Filter search results and queries by service
- **Storage Enhancements**: BaseStorageAdapter tracks service activity with timestamps
- **Type Definitions**: Added ServiceStatistics interface and extended StatisticsData
## Implementation Details
- Services automatically tracked via defaultService config or per-operation override
- Service status detection (active/inactive/read-only) based on activity
- Memory-efficient tracking at statistics level, not per noun/verb
- Backward compatible - existing data tracked under 'default' service
## Documentation
- Comprehensive guide in docs/guides/per-service-statistics.md
- Examples for multi-tenant apps, health monitoring, and auditing
- API reference and migration guide included
## Testing
- Full test suite in tests/service-statistics.test.ts
- Coverage of all new methods and filtering capabilities
This enables better observability, debugging, and management of multi-service Brainy deployments, addressing the need to track individual service performance when multiple services share storage.
