fix(ui): allow guidance slider to reach 1 for FLUX.2 Klein

[Pfannkuchensack]

Summary

FLUX.2 Klein models require guidance=1 (no CFG), but the guidance slider minimum was set to 2. Changed sliderMin from 2 to 1 to allow proper configuration for FLUX.2 Klein models.

Related Issues / Discussions

N/A

QA Instructions

1. Select a FLUX.2 Klein model
2. Open the Guidance slider in the generation settings
3. Verify the slider can now reach a minimum value of 1 (previously stopped at 2)
4. Generate an image with guidance=1 to confirm it works correctly

Merge Plan

This is a simple one-line change with no migration or breaking changes required.

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Tests added / updated (if applicable)
• ❗Changes to a redux slice have a corresponding migration
• Documentation added / updated (if applicable)
• Updated What's New copy (if doing a release after this PR)

[lstein]

Looks good!