feat(ops): add object storage management and site-mapping CSV import/export

Ship the Ops backstage 对象存储 page (browse / upload / move / delete /
folder ops) backed by a new object-storage service + handler, with the
shared storage client extended with List/Stat/Copy/Usage/DownloadURL so
both MinIO and Aliyun providers cover the new surface. Add
ForcePathStyle to the object-storage config and treat r2/s3/custom_s3
as external providers so Cloudflare R2 and other S3-compatibles can
share the MinIO client path without spinning up the bundled MinIO.

Also add CSV import/export + template download to the site-domain
mappings page, raise gin MaxMultipartMemory to 8 MiB for the new
multipart endpoints, register Ops swagger routes, and extend the
descriptions-parity test to cover the ops router.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/internal/shared/objectstorage/url.go

@@ -3,6 +3,7 @@ package objectstorage
 import (
 	"fmt"
 	"net/url"
+	"path/filepath"
 	"strings"
 
 	"github.com/geo-platform/tenant-api/internal/shared/config"
@@ -65,6 +66,66 @@ func buildPublicURL(cfg config.ObjectStorageConfig, objectKey string, bucketInHo
 	return endpointURL.String(), nil
 }
 
+func DownloadContentDisposition(objectKey string) string {
+	name := strings.TrimSpace(filepath.Base(strings.TrimRight(objectKey, "/")))
+	if name == "" || name == "." || name == "/" || name == "\\" {
+		name = "object"
+	}
+	name = strings.Map(func(r rune) rune {
+		if r == '"' || r == '\\' || r == '\r' || r == '\n' {
+			return -1
+		}
+		return r
+	}, name)
+	if name == "" {
+		name = "object"
+	}
+	return fmt.Sprintf(
+		`attachment; filename="%s"; filename*=UTF-8''%s`,
+		asciiContentDispositionFileName(name),
+		url.PathEscape(name),
+	)
+}
+
+func downloadContentDisposition(objectKey string) string {
+	return DownloadContentDisposition(objectKey)
+}
+
+func asciiContentDispositionFileName(name string) string {
+	var builder strings.Builder
+	for _, r := range name {
+		if r < 0x20 || r >= 0x7f || r == '"' || r == '\\' {
+			continue
+		}
+		builder.WriteRune(r)
+	}
+
+	fallback := strings.TrimSpace(builder.String())
+	if fallback == "" || fallback == "." || fallback == ".." || strings.HasPrefix(fallback, ".") {
+		return "object" + safeASCIIExtension(name)
+	}
+	return fallback
+}
+
+func safeASCIIExtension(name string) string {
+	ext := filepath.Ext(name)
+	if ext == "" || ext == "." {
+		return ""
+	}
+	var builder strings.Builder
+	for _, r := range ext {
+		if r < 0x20 || r >= 0x7f || r == '"' || r == '\\' {
+			continue
+		}
+		builder.WriteRune(r)
+	}
+	ext = strings.TrimSpace(builder.String())
+	if !strings.HasPrefix(ext, ".") || ext == "." {
+		return ""
+	}
+	return ext
+}
+
 func parseURLWithScheme(raw string, defaultScheme string) (*url.URL, error) {
 	raw = strings.TrimSpace(raw)
 	if raw == "" {