Remove complete time series aggregation example and add data collection service implementation

- Deleted `example_complete_series_aggregation.py` as it is no longer needed.
- Introduced `data_collection_service.py`, a production-ready service for cryptocurrency market data collection with clean logging and robust error handling.
- Added configuration management for multiple trading pairs and exchanges, supporting health monitoring and graceful shutdown.
- Created `data_collection.json` for service configuration, including exchange settings and logging preferences.
- Updated `CandleProcessingConfig` to reflect changes in timeframes for candle processing.
- Enhanced documentation to cover the new data collection service and its configuration, ensuring clarity for users.

scripts/start_data_collection.py

@@ -0,0 +1,140 @@
+#!/usr/bin/env python3
+"""
+Start Data Collection Service
+
+Simple script to start the cryptocurrency data collection service
+with clean console output and proper configuration.
+
+Usage:
+    python scripts/start_data_collection.py [options]
+
+Examples:
+    # Start with default configuration (indefinite run)
+    python scripts/start_data_collection.py
+    
+    # Run for 8 hours with default config
+    python scripts/start_data_collection.py --hours 8
+    
+    # Use custom configuration file
+    python scripts/start_data_collection.py --config config/my_config.json
+    
+    # Run for 24 hours with custom config
+    python scripts/start_data_collection.py --config config/production.json --hours 24
+"""
+
+import asyncio
+import argparse
+import sys
+from pathlib import Path
+
+# Add project root to path
+project_root = Path(__file__).parent.parent
+sys.path.insert(0, str(project_root))
+
+from data.collection_service import run_data_collection_service
+
+
+def display_banner(config_path: str, duration_hours: float = None):
+    """Display service startup banner."""
+    print("🚀 CRYPTOCURRENCY DATA COLLECTION SERVICE")
+    print("=" * 55)
+    print(f"📁 Configuration: {config_path}")
+    
+    if duration_hours:
+        print(f"⏱️  Duration: {duration_hours} hours")
+    else:
+        print("⏱️  Duration: Indefinite (until stopped)")
+    
+    print("📊 Logging: Essential events only (connections, errors)")
+    print("💾 Storage: PostgreSQL + Redis")
+    print("🔍 Monitor: python scripts/monitor_clean.py")
+    print("⏹️  Stop: Ctrl+C")
+    print("=" * 55)
+
+
+def main():
+    """Main entry point."""
+    parser = argparse.ArgumentParser(
+        description="Start Cryptocurrency Data Collection Service",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog="""
+Examples:
+  # Start with default configuration (indefinite)
+  python scripts/start_data_collection.py
+  
+  # Run for 8 hours
+  python scripts/start_data_collection.py --hours 8
+  
+  # Use custom configuration
+  python scripts/start_data_collection.py --config config/custom.json
+  
+  # Production run for 24 hours
+  python scripts/start_data_collection.py --config config/production.json --hours 24
+
+Configuration:
+  The service will create a default configuration file if none exists.
+  Default location: config/data_collection.json
+  
+  The configuration includes:
+  - Exchange settings (OKX by default)
+  - Trading pairs (BTC-USDT, ETH-USDT by default)
+  - Data types and timeframes
+  - Health monitoring settings
+        """
+    )
+    
+    parser.add_argument(
+        '--config', 
+        default="config/data_collection.json",
+        help='Configuration file path (default: config/data_collection.json)'
+    )
+    
+    parser.add_argument(
+        '--hours',
+        type=float,
+        help='Collection duration in hours (default: indefinite until Ctrl+C)'
+    )
+    
+    parser.add_argument(
+        '--quiet',
+        action='store_true',
+        help='Suppress banner and start directly'
+    )
+    
+    args = parser.parse_args()
+    
+    # Validate arguments
+    if args.hours is not None and args.hours <= 0:
+        print("❌ Duration must be positive")
+        sys.exit(1)
+    
+    # Display banner unless quiet mode
+    if not args.quiet:
+        display_banner(args.config, args.hours)
+    
+    try:
+        # Start the service
+        print("🎯 Starting service..." if not args.quiet else "")
+        
+        success = asyncio.run(run_data_collection_service(
+            config_path=args.config,
+            duration_hours=args.hours
+        ))
+        
+        if success:
+            print("✅ Service completed successfully" if not args.quiet else "")
+            sys.exit(0)
+        else:
+            print("❌ Service failed" if not args.quiet else "")
+            sys.exit(1)
+            
+    except KeyboardInterrupt:
+        print("\n👋 Service interrupted by user")
+        sys.exit(0)
+    except Exception as e:
+        print(f"❌ Fatal error: {e}")
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()