fix: correct error propagation from exec errors

[rawkode]

I'm submitting a

• bug fix
• feature
• documentation addition

What is the current behaviour?

Closes #316

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem

What is the expected behavior?

What is the motivation / use case for changing the behavior?

Please tell us about your environment:

Version (comtrya --version):
Operating system:

[codecov-commenter]

Codecov Report

Attention: 26 lines in your changes are missing coverage. Please review.

Comparison is base (2cf7391) 28.26% compared to head (7f73bb7) 28.59%.
Report is 3 commits behind head on main.

Files	Patch %	Lines
lib/src/atoms/command/exec.rs	18.75%	26 Missing ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #387      +/-   ##
==========================================
+ Coverage   28.26%   28.59%   +0.33%     
==========================================
  Files          85       85              
  Lines        2289     2301      +12     
==========================================
+ Hits          647      658      +11     
- Misses       1642     1643       +1     

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