chore: 初始化仓库基线（AGENTS.md、git 规范、敏感文件排除）

server-go/internal/middleware/cors.go

@@ -0,0 +1,50 @@
+package middleware
+
+import (
+	"strings"
+
+	"github.com/gin-gonic/gin"
+)
+
+// CORS 跨域中间件，限制允许的来源、方法和头
+func CORS() gin.HandlerFunc {
+	// 允许的来源：同源、本地开发、Tailscale 网段、局域网
+	allowedOrigins := []string{
+		"http://localhost:5174",
+		"http://localhost:3000",
+		"http://127.0.0.1:5174",
+		"http://127.0.0.1:3000",
+	}
+
+	isAllowed := func(origin string) bool {
+		for _, o := range allowedOrigins {
+			if origin == o {
+				return true
+			}
+		}
+		// 允许 Tailscale 100.x.x.x 和局域网 192.168.x.x 访问
+		if strings.HasPrefix(origin, "http://100.") || strings.HasPrefix(origin, "http://192.168.") ||
+			strings.HasPrefix(origin, "http://113.") || strings.HasPrefix(origin, "http://115.") {
+			return true
+		}
+		return false
+	}
+
+	return func(c *gin.Context) {
+		origin := c.GetHeader("Origin")
+		if origin != "" && isAllowed(origin) {
+			c.Header("Access-Control-Allow-Origin", origin)
+			c.Header("Access-Control-Allow-Methods", "GET, POST, PUT, PATCH, DELETE, OPTIONS")
+			c.Header("Access-Control-Allow-Headers", "Content-Type, Authorization, X-API-Key")
+			c.Header("Access-Control-Allow-Credentials", "true")
+			c.Header("Vary", "Origin")
+		}
+
+		if c.Request.Method == "OPTIONS" {
+			c.AbortWithStatus(204)
+			return
+		}
+
+		c.Next()
+	}
+}