refactor: remove unused remarks and add quick domain create

Drop remark fields from Zone, Zone domains, proxy routes, WAF rule
groups and IP groups across models, APIs, UI and DB columns (keep
certificate/origin remarks). Add quick-create domain input for short
labels, @ apex and full FQDNs when binding domains.

internal/apps/openflare/zone/errs.go

@@ -14,5 +14,5 @@ const (
 	errDomainExists              = "域名已存在"
 	errCertificateNotFound       = "所选证书不存在"
 	errDomainBoundToRoute        = "域名已绑定反代路由，请先解除绑定"
-	errZoneHasDomains            = "Zone 下仍有域名，请先删除全部域名"
+	errZoneHasDomains            = "根域下仍有域名，请先删除全部域名"
 )