BI-2901: Add backend VCF download endpoint for genotyping imports

[humsika]

Description

Story: 2901

Added backend support for downloading the original uploaded VCF file for completed genotype imports.

This change:

• adds genotypeImportId to the genotype imports list response so the frontend has an opaque per-row download identifier
  adds a new backend endpoint: GET /programs/{programId}/geno/imports/{genotypeImportId}/download
• validates that the requested genotype import belongs to the requested program
• restricts downloads to successful/completed genotype imports only
• streams the original uploaded VCF file back through bi-api as an attachment
• preserves the original uploaded filename in the download response
• keeps S3 bucket names, keys, and direct S3 URLs hidden from the frontend

Dependencies

bi-web: develop
bi-api: feature/bi-2901

Testing

1. Call the genotype imports list endpoint for a program with successful genotype imports.
2. Verify each returned row includes genotypeImportId.
3. Call: GET /v1/programs/{programId}/geno/imports/{genotypeImportId}/download
4. Verify the response is 200 OK for a valid completed genotype import.
5. Verify the response is streamed as an attachment and the Content-Disposition header contains the original uploaded .vcf filename.
6. Verify the response does not expose any S3 bucket name, object key, or direct S3 URL.
7. Verify failed, pending, or otherwise unavailable genotype imports are not downloadable.

Checklist:

• I have performed a self-review of my own code
• I have tested my code and ensured it meets the acceptance criteria of the story
• I have create/modified unit and/or integration tests to cover this change or tests are not applicable
• I have commented my code, particularly in hard-to-understand areas
• I have either updated the source of truth or arranged for update with product owner if needed https://breedinginsight.atlassian.net/wiki/spaces/BI/pages/1559953409/Source+of+Truth

[nickpalladino]

Looks good. Did some testing for the issue Heather mentioned:

2026-06-23 15:22:49.384-0400 [RxCachedThreadScheduler-1] ERROR o.b.a.v.c.InternalServerErrorHandler - Error Id: fa01a680-c97e-494a-96ed-15f0d3d57ad0
software.amazon.awssdk.services.s3.model.NoSuchBucketException: The specified bucket does not exist (Service: S3, Status Code: 404, Request ID: 6320c0d4-acc4-4141-88b8-b8b0ecfe40ce, Extended Request ID: s9lzHYrFp76ZVxRcpX9+5cjAnEH2ROuNkd2BHfIa6UkFVdtjf5mKR3/eTPFvsiP/XV/VLi31234=)

I wasn't able to reproduce this, uploaded multiple vcfs to the same submission without issue. Maybe a configuration issue with the bucket env.