fix: feature_segment missing in versioning

[SahilJat]

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Changes

Closes #7587

Fixes a 500 error that occurs when feature_segment is completely missing from feature_states_to_create.

Swapped fs["feature_segment"] for fs.get("feature_segment") in segment_ids_to_create_overrides to safely handle missing keys and prevent KeyError crashes. The existing validation now correctly catches this and returns a 400.

How did you test this code?

Added a test case verifying that a payload entirely missing the feature_segment key returns a 400 with the proper error message instead of a 500.

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[gemini-code-assist]

Code Review

This pull request fixes a potential KeyError (which resulted in a 500 Internal Server Error) when the feature_segment key is entirely omitted from the feature_states_to_create payload. By using .get("feature_segment") instead of direct key access, the code now safely handles missing keys. A unit test has also been added to verify that a 400 Bad Request is returned instead of a 500 error. I have no further feedback to provide as the changes are correct and well-tested.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.36%. Comparing base (482f0ff) to head (3bde472).
⚠️ Report is 14 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7618      +/-   ##
==========================================
- Coverage   98.51%   98.36%   -0.16%     
==========================================
  Files        1439     1439              
  Lines       54690    54577     -113     
==========================================
- Hits        53880    53685     -195     
- Misses        810      892      +82     

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[matthewelwell]

Thanks @SahilJat !

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3 Skipped Deployments

Project	Deployment	Actions	Updated (UTC)
docs	Ignored	Preview	May 29, 2026 3:20pm
flagsmith-frontend-preview	Ignored	Preview	May 29, 2026 3:20pm
flagsmith-frontend-staging	Ignored	Preview	May 29, 2026 3:20pm