Harden ingest PR filtering and ref path resolution

[stephenkilbourn]

Description

This PR hardens the Edit Ingest flow to prevent non-Github app PRs from being treated as editable ingests, and fixes ref normalization when resolving ingest JSON files.

Context

I saw a retrieve-ingest failure when a manual PR with non-standard refs (for example, collection/GEDI) was included in Edit Collection results. The UI then attempted to resolve a file path from that ref and GitHub Contents returned Not Found.

What Changed

• Added PR source/convention filtering in ListPRs.ts]
• Include PRs authored by bot accounts such as the veda-github-actor
• Otherwise include only PRs that match app conventions:
  • Title starts with collection Ingest Request for or dataset Ingest Request for
  • Head ref starts with feat/
• Added safer ref normalization in RetrieveJSON.ts
• Normalizes refs like:
  • refs/heads/collection/GEDI
  • collection/GEDI
  • feat/GEDI
• Updated tests to reflect and validate the new behavior:
  • ListPRs.test.ts
  • RetrieveJSON.test.ts
  • ListPRsFallback.test.ts

Behavior Change

Before:
Manual/non-conforming PRs could appear in Edit Ingest lists if they touched target paths.
Some refs produced incorrect file paths and caused retrieve-ingest failures.
After:
Only app-authored or convention-conforming PRs are eligible in list-ingests.
retrieve-ingest resolves ref-to-filename more defensively and consistently.