Design batched logging architecture and interfaces

## Objective

Design the architecture and interfaces for the batched logging system before implementation.

## Tasks

1. **Define Core Interfaces**
- `LogQueueManager` - Manages memory queues for different log types
- `BatchWriter` - Handles periodic/threshold-based batch writes
- `LogBuffer` - Memory buffer with configurable capacity
1. **Define Configuration**
- Batch size threshold (default: 100 items)
- Flush interval (default: 5 seconds)
- Queue capacity limits
- Redis backup settings (per log type)
1. **Design Data Flow**
- Log ingestion path (non-blocking)
- Batch assembly logic
- Flush trigger conditions (time-based, size-based)
- Error handling and retry logic
1. **Integration Points**
- Repository layer changes (add bulk insert methods)
- Service layer changes (replace direct DB calls)
- Configuration management (unified config)

## Deliverables

- Architecture document or design diagrams
- Interface definitions (Protocol classes)
- Configuration schema
- Integration plan

## Acceptance Criteria

- Clear separation between log ingestion and DB writing
- Support for different log types with different policies
- Graceful handling of backpressure scenarios
- Design reviewed and approved

JIRA Issue: BA-4232