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/configs/config.local.yaml.example

@@ -143,6 +143,7 @@ object_storage:
   use_ssl: false
   public_base_url: ""
   region: ""
+  force_path_style: false
   # Prefer environment override for secrets:
   # export OBJECT_STORAGE_ACCESS_KEY=minioadmin
   # export OBJECT_STORAGE_SECRET_KEY=minioadmin
@@ -151,6 +152,15 @@ object_storage:
   # endpoint: localhost:9000
   # bucket: geo-private
   # use_ssl: false
+  # force_path_style: true
+  #
+  # Cloudflare R2 / S3-compatible example:
+  # provider: r2
+  # endpoint: <account-id>.r2.cloudflarestorage.com
+  # bucket: your-bucket
+  # region: auto
+  # use_ssl: true
+  # force_path_style: true
   #
   # Aliyun OSS example:
   # provider: aliyun

server/configs/config.yaml

@@ -167,6 +167,7 @@ object_storage:
   object_acl: default
   signed_url_ttl: 30m
   region: cn-shanghai
+  force_path_style: false
 
 cache:
   driver: redis

server/configs/ops-config.yaml

@@ -52,6 +52,7 @@ object_storage:
   object_acl: default
   signed_url_ttl: 30m
   region: cn-shanghai
+  force_path_style: false
 
 log:
   level: info