docs: Update architecture docs with platform infrastructure details

- Add platform infrastructure chapter to frontend-backend architecture design
- Update system architecture document with 6 new infrastructure modules
- Update AI onboarding guide with infrastructure overview
- Link to backend/src/common/README.md for detailed usage guide

Key Updates:
- Storage service (LocalAdapter + OSSAdapter)
- Logging system (Winston + JSON format)
- Cache service (Memory + Redis)
- Async job queue (Memory + Database)
- Health check endpoints
- Monitoring metrics
- Database connection pool
- Environment config management

All modules support zero-code switching between local and cloud environments.

Related: #Platform-Infrastructure

docs/03-业务模块/AIA-AI智能问答/02-技术设计/01-数据库设计.md

@@ -525,3 +525,4 @@ id String @id @default(uuid())
 
 
 
+