feat(media): implement integrated media manager with sidebar and picker

- Implement DriveService and ShopifyMediaService for backend operations
- Create MediaSidebar.html with premium UI and auto-polling
- Integrate Google Picker API for robust file selection
- Orchestrate sync logic via MediaService (Drive -> Staged Upload -> Shopify)
- Add secure config handling for API keys and tokens
- Update ppsscript.json with required OAuth scopes
- Update MEMORY.md and README.md with architecture details

src/services/MockDriveService.ts

@@ -0,0 +1,55 @@
+import { IDriveService } from "../interfaces/IDriveService"
+
+export class MockDriveService implements IDriveService {
+  private folders: Map<string, any> = new Map() // id -> folder
+  private files: Map<string, any[]> = new Map() // folderId -> files
+
+  constructor() {
+    // Setup root folder mock if needed or just handle dynamic creation
+  }
+
+  getOrCreateFolder(folderName: string, parentFolderId: string): GoogleAppsScript.Drive.Folder {
+    // Mock implementation finding by name "under" parent
+    const key = `${parentFolderId}/${folderName}`
+    if (!this.folders.has(key)) {
+        const newFolder = {
+            getId: () => `mock_folder_${folderName}_id`,
+            getName: () => folderName,
+            getUrl: () => `https://mock.drive/folders/${folderName}`,
+            createFile: (blob) => this.saveFile(blob, `mock_folder_${folderName}_id`)
+        } as unknown as GoogleAppsScript.Drive.Folder;
+        this.folders.set(key, newFolder)
+    }
+    return this.folders.get(key)
+  }
+
+  saveFile(blob: GoogleAppsScript.Base.Blob, folderId: string): GoogleAppsScript.Drive.File {
+     const newFile = {
+        getId: () => `mock_file_${Date.now()}`,
+        getName: () => blob.getName(),
+        getBlob: () => blob,
+        getUrl: () => `https://mock.drive/files/${blob.getName()}`,
+        getLastUpdated: () => new Date()
+     } as unknown as GoogleAppsScript.Drive.File
+
+     if (!this.files.has(folderId)) {
+        this.files.set(folderId, [])
+     }
+     this.files.get(folderId).push(newFile)
+     console.log(`[MockDrive] Saved file ${newFile.getName()} to ${folderId}. Total files: ${this.files.get(folderId).length}`)
+     return newFile
+  }
+
+  getFiles(folderId: string): GoogleAppsScript.Drive.File[] {
+    return this.files.get(folderId) || []
+  }
+
+  getFileById(id: string): GoogleAppsScript.Drive.File {
+     // Naive lookup for mock
+      for (const fileList of this.files.values()) {
+        const found = fileList.find(f => f.getId() === id)
+        if (found) return found
+      }
+      throw new Error("File not found in mock")
+  }
+}