feat(core,storage,oci,registry-config): add streaming response support and configurable registry URLs across protocols

ts/core/interfaces.core.ts

@@ -88,6 +88,7 @@ export interface IAuthConfig {
 export interface IProtocolConfig {
   enabled: boolean;
   basePath: string;
+  registryUrl?: string;
   features?: Record<string, boolean>;
 }
 
@@ -160,6 +161,21 @@ export interface IStorageBackend {
    * Get object metadata
    */
   getMetadata(key: string): Promise<Record<string, string> | null>;
+
+  /**
+   * Get an object as a ReadableStream. Returns null if not found.
+   */
+  getObjectStream?(key: string): Promise<{ stream: ReadableStream<Uint8Array>; size: number } | null>;
+
+  /**
+   * Store an object from a ReadableStream.
+   */
+  putObjectStream?(key: string, stream: ReadableStream<Uint8Array>): Promise<void>;
+
+  /**
+   * Get object size without reading data (S3 HEAD request).
+   */
+  getObjectSize?(key: string): Promise<number | null>;
 }
 
 /**
@@ -215,10 +231,13 @@ export interface IRequestContext {
 }
 
 /**
- * Base response structure
+ * Base response structure.
+ * `body` is always a `ReadableStream<Uint8Array>` at the public API boundary.
+ * Internal handlers may return Buffer/string/object — the SmartRegistry orchestrator
+ * auto-wraps them via `toReadableStream()` before returning to the caller.
  */
 export interface IResponse {
   status: number;
   headers: Record<string, string>;
-  body?: any;
+  body?: ReadableStream<Uint8Array> | any;
 }