feat: 官网 + 管理端 + Gin/GORM 后端首个完整版本

- web/: 产品官网（Hero 事件流终端、功能矩阵、架构、快速开始、下载、博客 + Markdown 详情页），青瓷绿双主题
- admin/: 内容管理（JWT 登录、文章分页/搜索/CRUD、草稿与发布），embed 挂 /admin
- server/: Gin + GORM，MySQL（DSN 走 .env，SQLite 兜底）；规范落地：sundynix_ 表前缀、字符串雪花主键、snake_case 列名、统一响应信封、公共分页参数
- 双 SPA embed 单二进制部署，make build 一键出包

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server/internal/router/router.go

@@ -0,0 +1,86 @@
+package router
+
+import (
+	"io/fs"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+
+	"git.sundynix.cn/Blizzard/sundynix-site/server/internal/handler"
+	"git.sundynix.cn/Blizzard/sundynix-site/server/internal/middleware"
+	"git.sundynix.cn/Blizzard/sundynix-site/server/internal/pkg/resp"
+	"git.sundynix.cn/Blizzard/sundynix-site/server/internal/webfs"
+)
+
+func New(db *gorm.DB) (*gin.Engine, error) {
+	r := gin.New()
+	r.Use(gin.Logger(), gin.Recovery(), middleware.CORS())
+
+	// ── 公开 API ──
+	api := r.Group("/api")
+	{
+		api.GET("/healthz", func(c *gin.Context) {
+			resp.OK(c, gin.H{"status": "ok"})
+		})
+
+		posts := handler.NewPostHandler(db)
+		api.GET("/posts", posts.List)
+		api.GET("/posts/:slug", posts.Get)
+	}
+
+	// ── 管理端 API ──
+	adminAuth := handler.NewAdminAuthHandler()
+	api.POST("/admin/login", adminAuth.Login)
+
+	adminAPI := api.Group("/admin", middleware.Auth())
+	{
+		posts := handler.NewAdminPostHandler(db)
+		adminAPI.GET("/posts", posts.List)
+		adminAPI.POST("/posts", posts.Create)
+		adminAPI.GET("/posts/:id", posts.Get)
+		adminAPI.PUT("/posts/:id", posts.Update)
+		adminAPI.DELETE("/posts/:id", posts.Delete)
+	}
+
+	// ── 静态站点：/admin → 管理端，其余 → 用户端 ──
+	webDist, err := webfs.WebDist()
+	if err != nil {
+		return nil, err
+	}
+	adminDist, err := webfs.AdminDist()
+	if err != nil {
+		return nil, err
+	}
+	webServer := http.FileServer(http.FS(webDist))
+	adminServer := http.StripPrefix("/admin", http.FileServer(http.FS(adminDist)))
+
+	r.NoRoute(func(c *gin.Context) {
+		path := c.Request.URL.Path
+		if strings.HasPrefix(path, "/api/") {
+			resp.NotFound(c, "接口不存在")
+			return
+		}
+		if path == "/admin" || strings.HasPrefix(path, "/admin/") {
+			serveSPA(c, adminDist, adminServer, strings.TrimPrefix(path, "/admin"), "/admin/")
+			return
+		}
+		serveSPA(c, webDist, webServer, path, "/")
+	})
+
+	return r, nil
+}
+
+// serveSPA 真实文件直接吐，否则回退 index.html 交给前端路由。
+func serveSPA(c *gin.Context, dist fs.FS, server http.Handler, rel, fallback string) {
+	p := strings.TrimPrefix(rel, "/")
+	if p != "" {
+		if _, err := fs.Stat(dist, p); err == nil {
+			server.ServeHTTP(c.Writer, c.Request)
+			return
+		}
+	}
+	c.Request.URL.Path = fallback
+	server.ServeHTTP(c.Writer, c.Request)
+}