Always normalize defaults

[mauvilsa]

What does this PR do?

Before submitting

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• Did you update the documentation? (readme and public docstrings)
• Did you write unit tests such that there is 100% coverage on related code? (required for bug fixes and new features)
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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (9273463) to head (edd544e).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #983   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           27        27           
  Lines         9162      9168    +6     
=========================================
+ Hits          9162      9168    +6     

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[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge; no actionable correctness, security, or repository-rule violations were identified.

Summary

This PR makes default normalization consistent across argument registration and set_defaults, while preserving permissive handling of invalid defaults unless strict validation is enabled.

• Normalizes defaults through the standard type-checking path.
• Properly restores subcommand parsing context after each parse.
• Normalizes module objects to import paths outside instantiation.
• Improves help rendering for enum and callable defaults.
• Adds regression coverage and updates documentation and changelog entries.

_{Reviews (1) · Last reviewed commit: "Always normalize defaults"}

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud