Add Android APK fleet nodes with Crucible UI integration and tests.

APK wrapper registers platform=android via AETHERFORGE_PLATFORM; fleet UI shows robot icons, Android Access Depth probes, and a shortened mining onion timeline.

agent/client/syscheck.go

@@ -19,7 +19,7 @@ func CollectFullSysCheck(cfg config.RuntimeConfig, agentID string) *FullSysCheck
 	}
 	r := &FullSysCheckReport{
 		GeneratedAt: time.Now().UTC().Format(time.RFC3339),
-		Platform:    runtime.GOOS,
+		Platform:    cfg.RegistrationPlatform(),
 		Arch:        runtime.GOARCH,
 		OSVersion:   deploy.HostOSVersion(),
 		WorkerName:  cfg.WorkerName,