feat: declare and execute SCUM guided installs

platform/domain/resources.go

@@ -545,6 +545,13 @@ type RuntimeServerVerificationCheck struct {
 	Required  bool
 }
 
+// RuntimeServerPrerequisite is a plugin-declared named prerequisite resolved
+// only through Run's fixed, platform-specific installer catalog.
+type RuntimeServerPrerequisite struct {
+	Key  string
+	Kind string
+}
+
 // RuntimeServerDeploymentProfile is a frozen, game-specific deployment
 // template. It contains logical references only; Run resolves them locally.
 type RuntimeServerDeploymentProfile struct {
@@ -556,6 +563,7 @@ type RuntimeServerDeploymentProfile struct {
 	InstallRootKey     string
 	ConfigKey          string
 	ConfigFormat       string
+	Prerequisites      []RuntimeServerPrerequisite
 	ConfigMappings     []RuntimeServerConfigMapping
 	DiscoveryMarkers   []RuntimeServerDiscoveryMarker
 	VerificationChecks []RuntimeServerVerificationCheck
@@ -847,6 +855,8 @@ type ServerDeploymentUpdate struct {
 	StopCommand      string
 	StatusCommand    string
 	Shell            ServerCommandShell
+	ShellSet         bool
+	ClearFields      []string
 }
 
 // ServerDeploymentView is the intentionally redacted read model.
@@ -1068,6 +1078,7 @@ type ServerDeploymentPlan struct {
 	InstallRootKey     string
 	ConfigKey          string
 	ConfigFormat       string
+	Prerequisites      []RuntimeServerPrerequisite
 	ConfigMappings     []RuntimeServerConfigMapping
 	DiscoveryMarkers   []RuntimeServerDiscoveryMarker
 	VerificationChecks []RuntimeServerVerificationCheck
@@ -1773,6 +1784,7 @@ func CopyServerInstance(instance ServerInstance) ServerInstance {
 }
 
 func CopyRuntimeServerDeploymentProfile(profile RuntimeServerDeploymentProfile) RuntimeServerDeploymentProfile {
+	profile.Prerequisites = append([]RuntimeServerPrerequisite(nil), profile.Prerequisites...)
 	profile.SupportedTargets = append([]RuntimeTarget(nil), profile.SupportedTargets...)
 	profile.ConfigMappings = append([]RuntimeServerConfigMapping(nil), profile.ConfigMappings...)
 	profile.DiscoveryMarkers = append([]RuntimeServerDiscoveryMarker(nil), profile.DiscoveryMarkers...)
@@ -1792,6 +1804,7 @@ func CopyServerDeploymentPlan(plan *ServerDeploymentPlan) *ServerDeploymentPlan
 		return nil
 	}
 	copy := *plan
+	copy.Prerequisites = append([]RuntimeServerPrerequisite(nil), plan.Prerequisites...)
 	copy.ConfigMappings = append([]RuntimeServerConfigMapping(nil), plan.ConfigMappings...)
 	copy.DiscoveryMarkers = append([]RuntimeServerDiscoveryMarker(nil), plan.DiscoveryMarkers...)
 	copy.VerificationChecks = append([]RuntimeServerVerificationCheck(nil), plan.VerificationChecks...)
@@ -1824,6 +1837,7 @@ func CopyServerDeploymentDefinition(definition ServerDeploymentDefinition) Serve
 }
 
 func CopyServerDeploymentUpdate(update ServerDeploymentUpdate) ServerDeploymentUpdate {
+	update.ClearFields = CopyStringSlice(update.ClearFields)
 	update.RuntimeBindings = CopyStringMap(update.RuntimeBindings)
 	update.CreateInputs = CopyStringMap(update.CreateInputs)
 	return update