feat: 管理端网站监控，浏览量写入独立 monitor.db

请求日志按日 JSONL；page_views 不进主库，避免统计数据撑大 jiang13.db。

Co-authored-by: Cursor <cursoragent@cursor.com>

middleware/accesslog.go

@@ -0,0 +1,33 @@
+package middleware
+
+import (
+	"time"
+
+	"git.iioio.com/freefire/jiang13-forum/service"
+	"github.com/gin-gonic/gin"
+)
+
+// AccessLogMiddleware 服务端访问日志采集（受 monitor_enabled 控制；热路径仅入队，后台写 jsonl）
+func AccessLogMiddleware(mon *service.MonitorService) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		if mon == nil || !mon.Enabled() {
+			c.Next()
+			return
+		}
+		path := c.Request.URL.Path
+		if mon.ShouldSkip(path) {
+			c.Next()
+			return
+		}
+		start := time.Now()
+		c.Next()
+		status := c.Writer.Status()
+		bytes := int64(c.Writer.Size())
+		if bytes < 0 {
+			bytes = 0
+		}
+		dur := int(time.Since(start).Milliseconds())
+		row := mon.BuildAccessLog(c.Request, c.Request.RemoteAddr, status, bytes, dur)
+		mon.Enqueue(row)
+	}
+}