Merge redundant coordinators into unified coordinator architecture

Major refactoring:
- Created UnifiedCoordinator that combines HiveCoordinator and DistributedCoordinator
- Eliminated code duplication and architectural redundancy
- Unified agent management, task orchestration, and workflow execution
- Single coordinator instance replaces two global coordinators
- Backward compatibility maintained through state aliases

Key features of UnifiedCoordinator:
✅ Combined agent types: Ollama + CLI agents with unified management
✅ Dual task modes: Simple tasks + complex distributed workflows
✅ Performance monitoring: Prometheus metrics + adaptive load balancing
✅ Background processes: Health monitoring + performance optimization
✅ Redis integration: Distributed caching and coordination (optional)
✅ Database integration: Agent loading + task persistence preparation

API updates:
- Updated all API endpoints to use unified coordinator
- Maintained interface compatibility for existing endpoints
- Fixed attribute references for unified agent model
- Simplified dependency injection pattern

Architecture benefits:
- Single point of coordination eliminates race conditions
- Reduced memory footprint (one coordinator vs two)
- Simplified initialization and lifecycle management
- Consistent feature set across all orchestration modes
- Better separation of concerns within single coordinator class

This resolves the critical architectural issue of redundant coordinators
while maintaining full backward compatibility and adding enhanced features.

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

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

backend/app/api/cli_agents.py

@@ -10,7 +10,7 @@ from pydantic import BaseModel
 
 from ..core.database import get_db
 from ..models.agent import Agent as ORMAgent
-from ..core.hive_coordinator import HiveCoordinator, Agent, AgentType
+from ..core.unified_coordinator import UnifiedCoordinator, Agent, AgentType
 from ..cli_agents.cli_agent_manager import get_cli_agent_manager
 
 router = APIRouter(prefix="/api/cli-agents", tags=["cli-agents"])