feat: OpsxDB 桌面数据库客户端首版入库

含工作台/连库多引擎字段与 SSH·SSL、结果编辑、Redis 键浏览、
Tauri 桌面与 docs/落地页；排除本地构建产物与 sidecar 二进制。

apps/server/internal/docs/docs.go

@@ -0,0 +1,89 @@
+// Package docs：用户文档骨架（嵌入 HTML，侧栏+正文密度对齐工作台）。
+package docs
+
+import (
+	"embed"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+)
+
+//go:embed content assets template.html
+var files embed.FS
+
+type page struct {
+	Slug  string
+	Title string
+	Body  string
+}
+
+var order = []page{
+	{Slug: "install", Title: "安装与启动"},
+	{Slug: "connect", Title: "连库入门"},
+	{Slug: "workbench", Title: "工作台简介"},
+	{Slug: "faq", Title: "常见问题"},
+}
+
+type Handler struct {
+	tpl string
+}
+
+func New() *Handler {
+	raw, err := files.ReadFile("template.html")
+	if err != nil {
+		panic("docs: template.html 缺失: " + err.Error())
+	}
+	return &Handler{tpl: string(raw)}
+}
+
+func (h *Handler) Register(r *gin.Engine) {
+	r.GET("/docs", func(c *gin.Context) { c.Redirect(http.StatusFound, "/docs/install") })
+	r.GET("/docs/:slug", h.Page)
+	r.GET("/docs/assets/*file", h.Asset)
+}
+
+func (h *Handler) Page(c *gin.Context) {
+	slug := c.Param("slug")
+	bodyBytes, err := files.ReadFile("content/" + slug + ".html")
+	if err != nil {
+		c.Status(http.StatusNotFound)
+		return
+	}
+	title := slug
+	nav := strings.Builder{}
+	for _, p := range order {
+		cls := "nav-link"
+		if p.Slug == slug {
+			cls += " active"
+			title = p.Title
+		}
+		nav.WriteString(`<a class="` + cls + `" href="/docs/` + p.Slug + `">` + p.Title + `</a>`)
+	}
+	html := h.tpl
+	html = strings.ReplaceAll(html, "{{TITLE}}", title)
+	html = strings.ReplaceAll(html, "{{NAV}}", nav.String())
+	html = strings.ReplaceAll(html, "{{BODY}}", string(bodyBytes))
+	c.Header("Content-Type", "text/html; charset=utf-8")
+	c.Header("Cache-Control", "no-cache")
+	_, _ = c.Writer.WriteString(html)
+}
+
+func (h *Handler) Asset(c *gin.Context) {
+	name := strings.TrimPrefix(c.Param("file"), "/")
+	if strings.Contains(name, "..") {
+		c.Status(http.StatusBadRequest)
+		return
+	}
+	data, err := files.ReadFile("assets/" + name)
+	if err != nil {
+		c.Status(http.StatusNotFound)
+		return
+	}
+	ct := "application/octet-stream"
+	if strings.HasSuffix(name, ".css") {
+		ct = "text/css; charset=utf-8"
+	}
+	c.Header("Content-Type", ct)
+	c.Data(http.StatusOK, ct, data)
+}