Add Chrysalis ingestion wrapper

[tomvothecoder]

Description

This adds a scheduler-agnostic HPC archive ingestor entrypoint and a thin Chrysalis site wrapper for existing Jenkins-driven metadata ingestion.

• Closes [DevOps]: Scope automated metadata ingestion at other sites (prioritize Chrysalis first) #154
• Adds shared hpc_archive_ingestor module that delegates to existing NERSC ingestor
• Adds sites/chrysalis.sh wrapper with Chrysalis archive and state defaults plus required API env vars
• Documents shared ingestor and site-wrapper pattern in backend scripts README
• Adds test coverage for the generic HPC module entrypoint

Checklist

• Code follows project style guidelines
• Self-reviewed code
• No new warnings
• Tests added or updated (if needed)
• All tests pass (locally and CI/CD)
• Documentation/comments updated (if needed)
• Breaking change noted (if applicable)

Deployment Notes (if any)

No special deployment steps.

Local validation is currently blocked because PostgreSQL was unavailable at 127.0.0.1, so make backend-test and the targeted ingestion test file could not complete in this environment.

[TonyB9000]

@tomvothecoder Once I am clear on the boundaries to the term "NERSC ingestion wrapper", I should be able to comprehent "Chrysalis ingestion wrapper". The term "scheduler-agnostic" refers to Jenkins? (I always considered cron to be universal...).