Fix identifier matching logic when only deviation files are present for combination row

[nolanwelch]

An error is raised for the identifier s2r1 psychopy sub-3000147 due to no files appearing to be present:

Combination row arrow-alert_psychopy has no variables present in /home/data/NDClab/datasets/thrive-dataset/sourcedata/raw/s2_r1/psychopy/sub-3000147/

However, variables are present, but all relevant files are deviation files that contain additional info. The issue lies in how we build the list of present combination identifiers.

Currently, the logic:

• Loops over all combination rows
• Then loops over all present sub/ses/run tuples
• Pulls in identifiers that:
  • Match the combination row
  • Match sub/ses/run
  • Are not deviation files

This means if all relevant identifiers are tied to deviation files, none are matched, causing a false "no variables" error.

Fix Needed:
Rework logic to correctly handle cases where only deviation files are present, possibly by:

• Adjusting matching logic to include deviation files under certain conditions
• Adding fallback checks when all matching identifiers are excluded due to deviation status

Checklist:

• Audit current logic for constructing present combination identifiers
• Identify and isolate logic excluding deviation files
• Modify logic to consider deviation files when appropriate
• Add test case for sub-3000147 scenario (s2r1, psychopy, arrow-alert)
• Verify fix prevents false "no variables" error
• Document behavior of deviation files in identifier matching