refactor: remove legacy GPU services, keep latest aitbc-multimodal-gpu.service

GPU Services Cleanup - Complete:
✅ LEGACY GPU SERVICES REMOVED: Cleaned up old GPU services, kept latest implementation
- systemd/aitbc-gpu-miner.service: Removed (legacy simple mining client)
- systemd/aitbc-gpu-multimodal.service: Removed (intermediate version)
- systemd/aitbc-gpu-registry.service: Removed (demo service)
- systemd/aitbc-multimodal-gpu.service: Kept (latest advanced implementation)

✅ SERVICE DIRECTORIES CLEANED:
🗑️ aitbc-gpu-miner.service.d: Removed configuration directory
🗑️ aitbc-gpu-multimodal.service.d: Removed configuration directory
🗑️ aitbc-gpu-registry.service.d: Removed configuration directory
📁 aitbc-multimodal-gpu.service: Preserved with all configuration

✅ LATEST SERVICE ADVANTAGES:
🔧 aitbc-multimodal-gpu.service: Most advanced GPU service
👤 Standard User: Uses 'aitbc' user instead of 'debian'
📁 Standard Paths: Uses /opt/aitbc/ instead of /home/debian/
🎯 Module Structure: Proper Python module organization
🔒 Security: Comprehensive security settings and resource limits
📊 Integration: Proper coordinator API integration
📚 Documentation: Has proper documentation reference

✅ REMOVED SERVICES ANALYSIS:
❌ aitbc-gpu-miner.service: Basic mining client, non-standard paths
❌ aitbc-gpu-multimodal.service: Intermediate version, mixed paths
❌ aitbc-gpu-registry.service: Demo service, limited functionality
✅ aitbc-multimodal-gpu.service: Production-ready, standard configuration

✅ DOCUMENTATION UPDATED:
📚 Enhanced Services Guide: Updated references to use aitbc-multimodal-gpu
📝 Service Names: Changed aitbc-gpu-multimodal to aitbc-multimodal-gpu
🔧 Systemctl Commands: Updated service references
📋 Management Scripts: Updated log commands

✅ CLEANUP BENEFITS:
✅ Single GPU Service: One clear GPU service to manage
✅ No Confusion: No multiple similar GPU services
✅ Standard Configuration: Uses AITBC standards
✅ Better Maintenance: Only one GPU service to maintain
✅ Clear Documentation: References updated to latest service

✅ REMAINING GPU INFRASTRUCTURE:
🔧 aitbc-multimodal-gpu.service: Main GPU service (port 8011)
📁 apps/coordinator-api/src/app/services/gpu_multimodal_app.py: Service implementation
🎯 CUDA Integration: Proper GPU access controls
📊 Resource Management: Memory and CPU limits configured

RESULT: Successfully removed legacy GPU services and kept the latest aitbc-multimodal-gpu.service, providing a clean, single GPU service with proper configuration and updated documentation references.

docs/beginner/01_getting_started/ENHANCED_SERVICES_IMPLEMENTATION_GUIDE.md

@@ -119,7 +119,7 @@ cd /opt/aitbc/apps/coordinator-api
 
 # Check individual service logs
 ./manage_services.sh logs aitbc-multimodal
-./manage_services.sh logs aitbc-gpu-multimodal
+./manage_services.sh logs aitbc-multimodal-gpu
 ```
 
 ## 📊 Service Details
@@ -197,7 +197,7 @@ curl -X POST http://localhost:8011/process \
 ./manage_services.sh status
 
 # View service logs
-./manage_services.sh logs aitbc-gpu-multimodal
+./manage_services.sh logs aitbc-multimodal-gpu
 
 # Enable auto-start
 ./manage_services.sh enable
@@ -234,10 +234,10 @@ df -h
 systemctl status aitbc-multimodal.service
 
 # Audit service logs
-sudo journalctl -u aitbc-multimodal.service --since "1 hour ago"
+sudo journalctl -u aitbc-multimodal-gpu.service --since "1 hour ago"
 
 # Monitor resource usage
-systemctl status aitbc-gpu-multimodal.service --no-pager
+systemctl status aitbc-multimodal-gpu.service --no-pager
 ```
 
 ## 🐛 Troubleshooting