Add graceful SCUM stop, restart, and version update flow

SCUM 停止/重启/更新以前只有“结束进程”这一条路，插件没有声明任何优雅关闭方式，
平台也没有把停止后重新启动串起来。现在插件声明自己的关闭脚本，run 先执行它，
平台在停止或更新成功后再自动拉起服务。

run:
- lifecycle stop 支持插件声明的 gracefulStop（可执行文件、参数、环境、超时、
  fallback=report|terminate）；关闭命令超时且声明 report 时任务失败，不再默默杀进程。
- 新增 steam.update 依赖探针：调用 steamcmd +app_info_print 获取公开分支 buildid，
  与本地 steamapps/appmanifest_<appid>.acf 的 buildid 比较，输出
  installed/latest/update=yes|no|unknown。

platform:
- 新增 POST /api/v1/server-instances/{id}/restart 与 /update。
- restart 派发插件 stop 动作（走优雅关闭），终态成功后入队 start 作业。
- update 派发插件 install 动作；插件在更新前必须先优雅关闭 SCUM，关闭失败直接拒绝
  SteamCMD 更新，成功后平台再拉起服务。
- 依赖检查输入带上插件声明的服务器安装根目录，供 steam.update 读取 appmanifest。

plugin (SCUM server plugin 0.1.16):
- bin/scum-stop.cmd：解析已声明的可执行文件路径，定位同路径正在运行的 SCUMServer.exe，
  通过本地 RCON 公告并发送关闭命令，等待进程自行退出；不再使用 taskkill。
- bin/scum-rcon.ps1：插件自有的 Source RCON 客户端，从 UE4SS mod config.ini 读取
  密码/端口，密钥不离开本机。
- actions/stop.json 声明 gracefulStop；actions/install.json 更新前先执行同一关闭脚本。

platform_web:
- 服务器详情新增“重启”按钮和“SCUM 版本更新”面板；点“检查更新”查询公开分支版本，
  只有检测到更新时“更新版本”按钮才会置为可用并高亮，点击后先确认再派发更新任务。

platform/validator/runtime_profiles.go

@@ -14,6 +14,7 @@ import (
 var (
 	runtimeDLLModKeyPattern = regexp.MustCompile(`^[a-z0-9][a-z0-9_-]{0,79}$`)
 	runtimeDLLABIPattern    = regexp.MustCompile(`^[A-Za-z0-9._-]{1,80}$`)
+	steamAppIDPattern       = regexp.MustCompile(`^[0-9]{1,10}$`)
 )
 
 func ValidateGamePluginRuntimeProfiles(profiles domain.GamePluginRuntimeProfiles) error {
@@ -74,10 +75,17 @@ func ValidateGamePluginRuntimeProfiles(profiles domain.GamePluginRuntimeProfiles
 		violations = append(violations, validateProfileKey(prefix+".key", probe.Key)...)
 		violations = append(violations, recordRuntimeProfileKey(dependencyKeys, prefix+".key", probe.Key)...)
 		violations = append(violations, validateProfileKey(prefix+".targetKey", probe.TargetKey)...)
-		if !oneOf(probe.Kind, "command.version", "service.exists", "port.available", "steam.app", "java.version", "docker.available", "package.installed", "file.exists") {
+		if !oneOf(probe.Kind, "command.version", "service.exists", "port.available", "steam.app", "steam.update", "java.version", "docker.available", "package.installed", "file.exists") {
 			violations = append(violations, prefix+".kind is invalid")
 		}
 		violations = append(violations, validateSafeRuntimeValue(prefix+".minimumVersion", probe.MinimumVersion)...)
+		if probe.Kind == "steam.update" {
+			if !steamAppIDPattern.MatchString(probe.SteamAppID) {
+				violations = append(violations, prefix+".steamAppId is invalid for a Steam build probe")
+			}
+		} else if probe.SteamAppID != "" {
+			violations = append(violations, prefix+".steamAppId is allowed only for steam.update probes")
+		}
 		violations = append(violations, validateRuntimePlatforms(prefix+".platforms", probe.Platforms)...)
 	}
 	for i, plan := range profiles.InstallPlans {

platform/validator/runtime_profiles_test.go

@@ -24,3 +24,20 @@ func TestValidateGamePluginRuntimeProfilesRejectsManualStepExecutionFields(t *te
 		t.Fatalf("expected manual execution field rejection, got %v", err)
 	}
 }
+
+func TestValidateGamePluginRuntimeProfilesChecksSteamBuildProbeAppID(t *testing.T) {
+	valid := domain.GamePluginRuntimeProfiles{DependencyProbes: []domain.RuntimeDependencyProbe{{Key: "game-build", Kind: "steam.update", TargetKey: "steamcmd", SteamAppID: "3792580"}}}
+	if err := ValidateGamePluginRuntimeProfiles(valid); err != nil {
+		t.Fatalf("expected declared steam build probe to validate, got %v", err)
+	}
+
+	missing := domain.GamePluginRuntimeProfiles{DependencyProbes: []domain.RuntimeDependencyProbe{{Key: "game-build", Kind: "steam.update", TargetKey: "steamcmd"}}}
+	if err := ValidateGamePluginRuntimeProfiles(missing); err == nil || !strings.Contains(err.Error(), "steamAppId is invalid for a Steam build probe") {
+		t.Fatalf("expected missing steam app id rejection, got %v", err)
+	}
+
+	misplaced := domain.GamePluginRuntimeProfiles{DependencyProbes: []domain.RuntimeDependencyProbe{{Key: "java-21", Kind: "java.version", TargetKey: "java", SteamAppID: "3792580"}}}
+	if err := ValidateGamePluginRuntimeProfiles(misplaced); err == nil || !strings.Contains(err.Error(), "steamAppId is allowed only for steam.update probes") {
+		t.Fatalf("expected misplaced steam app id rejection, got %v", err)
+	}
+}

platform/validator/server_lifecycle.go

@@ -36,7 +36,7 @@ func ValidateServerLifecycleCommand(command domain.ServerLifecycleCommand) error
 
 func ValidateServerLifecycleAction(action domain.ServerLifecycleAction) error {
 	switch action {
-	case domain.ServerLifecycleActionCreate, domain.ServerLifecycleActionStart, domain.ServerLifecycleActionStop, domain.ServerLifecycleActionStatus:
+	case domain.ServerLifecycleActionCreate, domain.ServerLifecycleActionStart, domain.ServerLifecycleActionStop, domain.ServerLifecycleActionRestart, domain.ServerLifecycleActionUpdate, domain.ServerLifecycleActionStatus:
 		return nil
 	default:
 		return ValidationError{Violations: []string{fmt.Sprintf("action %q is invalid", action)}}