add UUID sanity check

[ericphanson]

closes #603, code copied from that issue via claude

based on #631 which should be merged first

[codecov]

Codecov Report

❌ Patch coverage is 92.85714% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 48.13%. Comparing base (3e3628f) to head (d0bdee8).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
AutoMerge/src/guidelines.jl	92.85%	1 Missing ⚠️

❌ Your project status has failed because the head coverage (48.13%) is below the target coverage (70.00%). You can increase the head coverage or adjust the target coverage.

❗ There is a different number of reports uploaded between BASE (3e3628f) and HEAD (d0bdee8). Click for more details.

HEAD has 13 uploads less than BASE

Flag	BASE (3e3628f)	HEAD (d0bdee8)
	24	11

Additional details and impacted files

@@             Coverage Diff             @@
##           master     #642       +/-   ##
===========================================
- Coverage   78.25%   48.13%   -30.12%     
===========================================
  Files          29       29               
  Lines        1922     1928        +6     
===========================================
- Hits         1504      928      -576     
- Misses        418     1000      +582     

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The base branch was changed.

[ericphanson]

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we need JuliaWeb/GitHub.jl#233 !