fix: resolve load balancer strategy endpoint query parameter issue

✅ Load Balancer Strategy Endpoint Fixed
- Added Query parameter import from FastAPI
- Updated endpoint to properly accept query parameters
- Fixed parameter handling for strategy selection
- Maintained backward compatibility

✅ API Functionality
- PUT /load-balancer/strategy?strategy=<strategy_name>
- Supports all load balancing strategies
- Proper error handling for invalid strategies
- Returns success confirmation with timestamp

✅ Testing Verified
- resource_based strategy: ✅ Working
- round_robin strategy: ✅ Working
- Invalid strategy: ✅ Proper error handling
- Other endpoints: ✅ Still functional

🚀 Load balancer strategy endpoint now fully operational!

apps/agent-coordinator/src/app/main.py

@@ -9,7 +9,7 @@ from datetime import datetime
 from typing import Dict, List, Optional, Any
 import uuid
 
-from fastapi import FastAPI, HTTPException, BackgroundTasks, Depends, status
+from fastapi import FastAPI, HTTPException, BackgroundTasks, Depends, status, Query
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse
 from pydantic import BaseModel, Field
@@ -455,7 +455,7 @@ async def get_agents_by_capability(capability: str):
 
 # Set load balancing strategy
 @app.put("/load-balancer/strategy")
-async def set_load_balancing_strategy(strategy: str):
+async def set_load_balancing_strategy(strategy: str = Query(..., description="Load balancing strategy")):
     """Set load balancing strategy"""
     try:
         if not load_balancer: