fix: complete OPC system implementation
- Add database connection retry logic (3 attempts, 5s delay)
- Add missing database functions: get_task_by_id, get_agent_execution, approve_agent_execution, update_agent_config, update_execution_status
- Complete agent execution approval workflow
- Fix agent executor to handle approved executions
- Fix inefficient task queries (use direct ID lookup)
- Add error action handling in agent executor
- Improve LiteLLM error handling with specific exception types
- Reduce LiteLLM timeout from 60s to 30s
- Fix execution status update to only set started_at once
- Consolidate WebSocket datetime serialization with helper function
- Implement update agent endpoint
Gan, Jimmy
5da2ae01a0