feat(admin): add security and activity management features

lib/server/validation.go

@@ -3,6 +3,7 @@ package server
 import (
 	"fmt"
 	"net/http"
+	"strconv"
 	"strings"
 
 	"github.com/gin-gonic/gin"
@@ -153,3 +154,36 @@ func (app *App) maxRequestBodyBytes() int64 {
 	}
 	return limit + 10*1024*1024
 }
+
+func (app *App) enforceUploadRateLimit(ctx *gin.Context, size int64) bool {
+	ip := clientIP(ctx)
+	if app.securityGuard.IsWhitelisted(ip) || app.securityGuard.IsAdminWhitelisted(ip) {
+		return true
+	}
+	allowed, requestCount, totalBytes := app.securityGuard.AllowUpload(
+		ip,
+		size,
+		app.config.SecurityUploadWindowSeconds,
+		app.config.SecurityUploadMaxRequests,
+		app.config.SecurityUploadMaxBytes,
+	)
+	if allowed {
+		return true
+	}
+
+	app.logActivity("security.upload_limit", "high", "Upload rate limit exceeded", ctx, map[string]string{
+		"requests": strconv.Itoa(requestCount),
+		"bytes":    strconv.FormatInt(totalBytes, 10),
+	})
+	app.createAlert(
+		"Upload rate limit triggered",
+		"medium",
+		"security",
+		"430",
+		"security.upload.rate_limit",
+		"Per-IP upload rate limit blocked request.",
+		map[string]string{"ip": ip, "requests": strconv.Itoa(requestCount)},
+	)
+	ctx.JSON(http.StatusTooManyRequests, gin.H{"error": "Too many uploads from this IP. Try again later."})
+	return false
+}