[file-transfer] Support additional file transfer destinations beyond S3 and Azure Blob Storage

[Ilja Herdt (Airbyte) (iherdt-airbyte)]

The file transfer feature currently only supports two destinations: S3 (v1.4.0+) and Azure Blob Storage (v1.1.6+). Sources that support file transfer (e.g., Google Drive, SFTP, Azure Blob Storage) cannot deliver files to warehouse destinations like Snowflake, GCS, or BigQuery.

Request: Expand file transfer destination support to include Snowflake (via internal/external stage), GCS, and other warehouse or object-store destinations.

Context: Organizations using file-based sources (Google Drive, SFTP) to sync structured files (.xlsx, .csv) into warehouse destinations have no native Airbyte path today. The current workaround is to land files in S3 via Airbyte file transfer and then use external tooling (e.g., Snowflake COPY INTO from an S3 stage) to complete the pipeline. This adds operational overhead and monitoring outside of Airbyte.

Expected behavior:

• File transfer sources should be able to deliver files to Snowflake (via internal or external stage), GCS, and BigQuery
• The destination connector should handle staging and loading automatically
• This would eliminate the need for intermediary object stores and external orchestration

Related issues:

• Support for blob transfers #25786 — Support for blob transfers
• [Roadmap] File Transfers #48420 — Roadmap: File Transfers (completed)
• [source-google-drive] Add file transfers support to google drive #51540 — source-google-drive: Add file transfers support (completed)