feat(ai-gateway): replace Step 3.5 Flash with Step 3.7 Flash (free)

[kilo-code-bot]

Summary

Renames the disabled StepFun free Kilo-exclusive model from Step 3.5 Flash to Step 3.7 Flash and adds the vision flag.

• Updated stepfun_37_flash_free_model (public/internal IDs, display name, description) in apps/web/src/lib/ai-gateway/providers/stepfun.ts.
• Added the vision flag alongside reasoning.
• Left the model status: 'disabled'.
• Updated references in apps/web/src/lib/ai-gateway/models.ts.
• The old stepfun/step-3.5-flash:free slug remains in forbiddenFreeModelIds so stale clients get an appropriate error.

Verification

N/A — config-only change; the model remains disabled.

Visual Changes

N/A

Reviewer Notes

The model stays disabled, so it is not exposed via autoFreeModels/preferredModels yet.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Executive Summary

Clean config-only rename of StepFun Step 3.5 Flash → 3.7 Flash; the old model ID is correctly preserved in forbiddenFreeModelIds, the model stays disabled, and all references are consistently updated.

Files Reviewed (2 files)

• apps/web/src/lib/ai-gateway/providers/stepfun.ts
• apps/web/src/lib/ai-gateway/models.ts

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_{Reviewed by claude-sonnet-4.6 · 370,070 tokens}

_{Review guidance: REVIEW.md from base branch main}