Google Drive as Data Source (Replace Azure Blob)

[jgilewicz]

Replace Azure Blob in data_acquisition.py with Google Drive as the pipeline data source.

• Authenticate via Google Drive API (service account JSON, stored as secret)
• List files from Drive folder (support PDF, DOCX, TXT)
• Download to temp dir, then pass paths to ocr_extraction
• Add GOOGLE_DRIVE_FOLDER_ID, GOOGLE_SERVICE_ACCOUNT_JSON to .env.example
• Handle pagination for folders exceeding 100 files