feat: implement agent migration system

- Fix config version inflation bug in main.go
- Add dynamic subsystem checking to prevent false change detection
- Implement migration detection and execution system
- Add directory migration from /etc/aggregator to /etc/redflag
- Update all path references across codebase to use new directories
- Add configuration schema versioning and automatic migration
- Implement backup and rollback capabilities
- Add security feature detection and hardening
- Update installation scripts and sudoers for new paths
- Complete Phase 1 migration system

aggregator-agent/cmd/agent/subsystem_handlers.go

@@ -830,7 +830,7 @@ func loadCachedPublicKeyDirect() ([]byte, error) {
 	if runtime.GOOS == "windows" {
 		keyPath = "C:\\ProgramData\\RedFlag\\server_public_key"
 	} else {
-		keyPath = "/etc/aggregator/server_public_key"
+		keyPath = "/etc/redflag/server_public_key"
 	}
 
 	data, err := os.ReadFile(keyPath)