feat: 工具配置 Ubuntu 化 + nvm 管理 Node 版本

- 工具目录重写为 Ubuntu 构建环境导向（7 项），每项带安装命令提示
  （apt/nvm，未安装时一键复制）
- 新增 nvm 工具条目（真实检测，本机验证 0.40.6）；Node.js 改为
  nvm 管理：默认版本可调，构建时通过 nvm install $NODE_VERSION
  灵活指定版本
- DeployTool 新增 installHint 字段（模型/更新白名单/seed）
- 新增 deploy/Dockerfile.buildnode：Ubuntu 22.04 + JDK17/Maven/Git/
  Docker CLI/Golang + nvm 默认 Node（--build-arg NODE_VERSION 可改）
- 工具页顶部说明条更新构建环境建议

backend/internal/database/database.go

@@ -224,7 +224,7 @@ func seedResources() {
 	}
 }
 
-// seedTools 工具清单（CheckCommand 为真实版本探测命令，安装走保守检测策略）
+// seedTools 工具清单（Ubuntu 构建环境导向；Node 由 nvm 管理默认版本，构建时可按需 nvm install）
 func seedTools() {
 	var n int64
 	DB.Model(&model.DeployTool{}).Count(&n)
@@ -232,11 +232,12 @@ func seedTools() {
 		return
 	}
 	DB.Create([]model.DeployTool{
-		{ToolKey: "jdk", DisplayName: "JDK", Category: "build", Version: "17", InstallMode: "preinstalled", Path: "/usr/lib/jvm/java-17", CheckCommand: "java -version", SortOrder: 1},
-		{ToolKey: "maven", DisplayName: "Maven", Category: "build", Version: "3.9", InstallMode: "lazy", Path: "/opt/maven", CheckCommand: "mvn -version", SortOrder: 2},
-		{ToolKey: "golang", DisplayName: "Golang", Category: "build", Version: "1.24", InstallMode: "preinstalled", Path: "/usr/local/go", CheckCommand: "go version", SortOrder: 3},
-		{ToolKey: "nodejs", DisplayName: "Node.js", Category: "build", Version: "20", InstallMode: "lazy", Path: "/usr/local/nvm", CheckCommand: "node -v", SortOrder: 4},
-		{ToolKey: "git", DisplayName: "Git", Category: "build", Version: "2.40", InstallMode: "preinstalled", Path: "/usr/bin/git", CheckCommand: "git --version", SortOrder: 5},
-		{ToolKey: "docker-cli", DisplayName: "Docker CLI", Category: "deploy", Version: "26", InstallMode: "lazy", Path: "/usr/bin/docker", CheckCommand: "docker --version", SortOrder: 6},
+		{ToolKey: "jdk", DisplayName: "JDK", Category: "build", Version: "17", InstallMode: "preinstalled", Path: "/usr/lib/jvm/java-17-openjdk-amd64", CheckCommand: "java -version", InstallHint: "apt update && apt install -y openjdk-17-jdk", SortOrder: 1},
+		{ToolKey: "maven", DisplayName: "Maven", Category: "build", Version: "3.8", InstallMode: "lazy", Path: "/usr/share/maven", CheckCommand: "mvn -version", InstallHint: "apt install -y maven", SortOrder: 2},
+		{ToolKey: "golang", DisplayName: "Golang", Category: "build", Version: "1.24", InstallMode: "preinstalled", Path: "/usr/local/go", CheckCommand: "go version", InstallHint: "apt install -y golang-1.24-go 或官方 tar 包解压至 /usr/local/go", SortOrder: 3},
+		{ToolKey: "nvm", DisplayName: "nvm（Node 版本管理）", Category: "build", Version: "0.40", InstallMode: "preinstalled", Path: "$HOME/.nvm", CheckCommand: `. "$HOME/.nvm/nvm.sh" && nvm --version`, InstallHint: "curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash", SortOrder: 4},
+		{ToolKey: "nodejs", DisplayName: "Node.js（nvm 管理）", Category: "build", Version: "20", InstallMode: "lazy", Path: "$HOME/.nvm/versions/node", CheckCommand: "node -v", InstallHint: "nvm install 20 && nvm alias default 20（构建时可用 nvm install 18 按需切版本）", SortOrder: 5},
+		{ToolKey: "git", DisplayName: "Git", Category: "build", Version: "2.40", InstallMode: "preinstalled", Path: "/usr/bin/git", CheckCommand: "git --version", InstallHint: "apt install -y git", SortOrder: 6},
+		{ToolKey: "docker-cli", DisplayName: "Docker CLI", Category: "deploy", Version: "26", InstallMode: "lazy", Path: "/usr/bin/docker", CheckCommand: "docker --version", InstallHint: "apt install -y docker.io", SortOrder: 7},
 	})
 }

backend/internal/handler/resources.go

@@ -448,7 +448,7 @@ func UpdateTool(c *gin.Context) {
 	}
 	var raw map[string]any
 	_ = c.ShouldBindJSON(&raw)
-	for _, k := range []string{"installMode", "version", "path", "enabled"} {
+	for _, k := range []string{"installMode", "version", "path", "installHint", "enabled"} {
 		if v, ok := raw[k]; ok {
 			database.DB.Model(&t).Update(k, v)
 		}

backend/internal/model/models.go

@@ -225,6 +225,7 @@ type DeployTool struct {
 	InstallMode     string     `gorm:"default:lazy" json:"installMode"` // preinstalled|lazy|disabled
 	Path            string     `json:"path"`
 	CheckCommand    string     `gorm:"type:text" json:"checkCommand"` // 真实版本探测命令
+	InstallHint     string     `gorm:"type:text" json:"installHint"`  // 安装命令提示（Ubuntu apt / nvm）
 	Enabled         bool       `gorm:"default:true" json:"enabled"`
 	LastCheck       *time.Time `json:"lastCheck"`
 	ErrorMsg        string     `json:"errorMsg"`

backend/static/index.html

@@ -1,14 +1,10 @@
-<!doctype html>
+<!DOCTYPE html>
 <html lang="zh-CN">
-  <head>
-    <meta charset="UTF-8" />
-    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
-    <title>FlowStack · 发布系统</title>
-    <script type="module" crossorigin src="/assets/index-Ddr58eTO.js"></script>
-    <link rel="stylesheet" crossorigin href="/assets/index-C7Y81iLv.css">
-  </head>
-  <body>
-    <div id="root"></div>
-  </body>
+<head><meta charset="UTF-8"><title>FlowStack</title></head>
+<body style="font-family: -apple-system, sans-serif; display: flex; align-items: center; justify-content: center; height: 100vh; margin: 0; background: #f6f8fa;">
+<div style="text-align: center; color: #57606a;">
+  <h1 style="font-size: 20px;">FlowStack 前端尚未构建</h1>
+  <p>请在项目根目录执行 <code style="background:#eaeef2;padding:2px 6px;border-radius:4px;">./run.sh build</code> 生成前端产物后重新编译。</p>
+</div>
+</body>
 </html>