feat(upstream): Add upstream proxy/cache subsystem and integrate per-protocol upstreams

ts/composer/classes.composerregistry.ts

@@ -7,6 +7,7 @@ import { BaseRegistry } from '../core/classes.baseregistry.js';
 import type { RegistryStorage } from '../core/classes.registrystorage.js';
 import type { AuthManager } from '../core/classes.authmanager.js';
 import type { IRequestContext, IResponse, IAuthToken } from '../core/interfaces.core.js';
+import type { IProtocolUpstreamConfig } from '../upstream/interfaces.upstream.js';
 import { isBinaryData, toBuffer } from '../core/helpers.buffer.js';
 import type {
   IComposerPackage,
@@ -22,24 +23,41 @@ import {
   generatePackagesJson,
   sortVersions,
 } from './helpers.composer.js';
+import { ComposerUpstream } from './classes.composerupstream.js';
 
 export class ComposerRegistry extends BaseRegistry {
   private storage: RegistryStorage;
   private authManager: AuthManager;
   private basePath: string = '/composer';
   private registryUrl: string;
+  private upstream: ComposerUpstream | null = null;
 
   constructor(
     storage: RegistryStorage,
     authManager: AuthManager,
     basePath: string = '/composer',
-    registryUrl: string = 'http://localhost:5000/composer'
+    registryUrl: string = 'http://localhost:5000/composer',
+    upstreamConfig?: IProtocolUpstreamConfig
   ) {
     super();
     this.storage = storage;
     this.authManager = authManager;
     this.basePath = basePath;
     this.registryUrl = registryUrl;
+
+    // Initialize upstream if configured
+    if (upstreamConfig?.enabled) {
+      this.upstream = new ComposerUpstream(upstreamConfig);
+    }
+  }
+
+  /**
+   * Clean up resources (timers, connections, etc.)
+   */
+  public destroy(): void {
+    if (this.upstream) {
+      this.upstream.stop();
+    }
   }
 
   public async init(): Promise<void> {
@@ -161,7 +179,26 @@ export class ComposerRegistry extends BaseRegistry {
     token: IAuthToken | null
   ): Promise<IResponse> {
     // Read operations are public, no authentication required
-    const metadata = await this.storage.getComposerPackageMetadata(vendorPackage);
+    let metadata = await this.storage.getComposerPackageMetadata(vendorPackage);
+
+    // Try upstream if not found locally
+    if (!metadata && this.upstream) {
+      const [vendor, packageName] = vendorPackage.split('/');
+      if (vendor && packageName) {
+        const upstreamMetadata = includeDev
+          ? await this.upstream.fetchPackageDevMetadata(vendor, packageName)
+          : await this.upstream.fetchPackageMetadata(vendor, packageName);
+
+        if (upstreamMetadata && upstreamMetadata.packages) {
+          // Store upstream metadata locally
+          metadata = {
+            packages: upstreamMetadata.packages,
+            lastModified: new Date().toUTCString(),
+          };
+          await this.storage.putComposerPackageMetadata(vendorPackage, metadata);
+        }
+      }
+    }
 
     if (!metadata) {
       return {