Fix gff3_merge crash on non-numeric root IDs

[MonicaPoelchau-USDA]

No description provided.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 56.28%. Comparing base (ea8ff0b) to head (09843c8).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #148      +/-   ##
==========================================
+ Coverage   56.24%   56.28%   +0.04%     
==========================================
  Files          28       28              
  Lines        5378     5383       +5     
==========================================
+ Hits         3025     3030       +5     
  Misses       2353     2353              

Files with missing lines	Coverage Δ
gff3tool/lib/replace_OGS.py	37.64% <100.00%> (+0.46%)	⬆️

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Pull request overview

This PR prevents gff3_merge from crashing when root feature IDs don’t contain a numeric suffix by making Groups.name2id() derive idprefix more defensively.

Changes:

• Avoids assuming roots[0]['attributes']['ID'] matches (.+?)(\d+) by scanning roots until a numeric-suffix ID is found.
• Initializes idprefix safely when no numeric-suffix root IDs exist.

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[ChrisChilders-USDA]

I think that this should work.