feat(admin): 资源与策略 - 后台统一维护账号配额与运行时请求限制 (#37)

Fixes #35

Co-authored-by: ddCat <ddcat666@88.com>

backend/internal/handler/security.go

@@ -20,8 +20,6 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-const maxSystemProxyBodyBytes int64 = 64 << 20
-
 var (
 	runtimeService        *service.Service
 	geminiGeneratePath    = regexp.MustCompile(`^/models/([^/:]+):(generateContent|streamGenerateContent)$`)
@@ -120,6 +118,15 @@ func enforceRateLimit(c *gin.Context, key string, limit int, window time.Duratio
 	return false
 }
 
+func loadRuntimePolicy(c *gin.Context, svc *service.Service) (service.RuntimePolicySetting, bool) {
+	policy, err := svc.RuntimePolicy()
+	if err != nil {
+		fail(c, http.StatusServiceUnavailable, errors.New("读取运行时策略失败："+err.Error()))
+		return service.RuntimePolicySetting{}, false
+	}
+	return policy, true
+}
+
 func authorizeSystemProxy(channel *model.ModelChannel, method string, requestPath string, contentType string, body []byte) error {
 	requestPath, err := normalizedProxyPath(requestPath)
 	if err != nil {