added cp314 support

[markleader]

Summary

Fixes Issue #59 by adding Python 3.14 wheel support and preparing the 3.1.1 release metadata.

Changes

• Added cp314-* to the publish workflow.
• Added smoke-test execution for built wheels in CI.
• Bumped project version metadata to 3.1.1.
• Moved unreleased changelog entries into the new 3.1.1 section.

Testing

• Not run locally for this branch.
• CI publish workflow now runs wheel smoke tests.

Compatibility / Numerical behavior

• No expected changes to numerical results
• Expected changes (explain and provide validation)