fix: add testcase with fractional with single entry

[leakonvalinka]

This PR

• adds a testcase with a flag with just a single fractional entry

Related Issues

part of open-feature/flagd#1924

Notes

the fractional operator still needs to be adjusted

Follow-up Tasks

How to test

[gemini-code-assist]

Code Review

This pull request adds a new test case for fractional flags with a single entry to ensure they always resolve to the specified variant. The changes involve adding flag definitions to JSON files and corresponding Gherkin scenarios. The review feedback suggests correcting inconsistent step wording, adding version tags for broader test coverage, and reordering scenarios for better logical grouping.

[gemini-code-assist]

Inconsistent step wording. This file uses fallback value (e.g., lines 12, 36, 54) instead of default value. Please update for consistency with the rest of the file to ensure the test harness correctly identifies the step.

    Given a String-flag with key "fractional-single-entry-flag" and a fallback value "fallback"

[leakonvalinka]

resolved in following commit. is there a reason why the testcases in evaluator/ use "fallback" and the ones in targeting.feature use "default"?

[gemini-code-assist]

This scenario is only tagged with @fractional-v2. Consider adding @fractional-v1 as well, as the expected behavior for a single-entry fractional rule should be consistent across both bucketing implementations. Additionally, the placement of this scenario separates two related 'shared seed' scenarios (lines 53 and 81); moving it before line 53 or after line 102 would improve logical grouping.

[gemini-code-assist]

This scenario is only tagged with @fractional-v2. Consider adding @fractional-v1 as well to ensure coverage for both bucketing implementations, as this test case is not specific to the v2 logic.

[leakonvalinka]

In my understanding this is indeed just a fractional-v2 feature