- Update Backend.Put method signature in storage.go to return (PutResult, error).
- Adjust all backend implementations (local, oss, s3, webdav) to return a PutResult enclosing Key and Bucket.
- Refactor storeUploadFile in upload routers.go to extract key/bucket from PutResult, eliminating manual config bucket lookups.
- Remove the unused cfgBucket helper from storage_ops.go.
- Adjust storage_migration_task.go and tests to accommodate the updated method signature.
Move storage backend configuration from startup YAML to system_config-backed runtime configuration. Add local, S3-compatible, R2, MinIO, OSS, and WebDAV backend support.
Add a storage migration async task using the existing task dispatch framework. Migration target config is carried in task payload, and maintenance mode is derived from task execution state.
Split upload file management and storage operations, add the admin storage configuration tab, and update migrations and Swagger docs.