feat(rate-limit): add default request rate limit configuration

- Support openresty_default_limit_req_per_ip in system_configs.
- Add limit_req and limit_req_status 429 directive generation in openresty renderer.
- Implement route-level limit_req_per_ip override and explicit disable.
- Add frontend UI inputs and validation in rate limits tab config.
- Update swagger API docs and changelog for v3.4.3-beta.3.

internal/apps/openflare/option/openresty_validators.go

@@ -53,6 +53,7 @@ var openRestyOptionValidators = map[string]func(key, value string) error{
 	model.ConfigKeyOpenRestyDefaultLimitConnPerServer:    validateNonNegativeIntegerOption,
 	model.ConfigKeyOpenRestyDefaultLimitConnPerIP:        validateNonNegativeIntegerOption,
 	model.ConfigKeyOpenRestyDefaultLimitRate:             validateOpenRestyDefaultLimitRate,
+	model.ConfigKeyOpenRestyDefaultLimitReqPerIP:         validateOpenRestyDefaultLimitReqPerIP,
 }
 
 var openRestyDefaultLimitRatePattern = regexp.MustCompile(`^\d+[kKmM]?$`)
@@ -194,3 +195,15 @@ func validateOpenRestyDefaultLimitRate(key, trimmed string) error {
 	}
 	return nil
 }
+
+var openRestyDefaultLimitReqPerIPPattern = regexp.MustCompile(`^\d+r/[sm]$`)
+
+func validateOpenRestyDefaultLimitReqPerIP(key, trimmed string) error {
+	if trimmed == "" || trimmed == "0" {
+		return nil
+	}
+	if !openRestyDefaultLimitReqPerIPPattern.MatchString(strings.ToLower(trimmed)) {
+		return fmt.Errorf("%s 格式不合法，请输入类似 10r/s、100r/m，或留空关闭", key)
+	}
+	return nil
+}