feat(apollo-wind): add maxRef to slider for dynamic max from another field

[Holychung]

Summary

SliderFieldMetadata.max was a static number — fine for fixed ranges (e.g. temperature: 0..1) but a poor fit when the upper bound depends on another field. The motivating case: an agent's maxTokenPerResponse slider should cap at the selected model's maxTokens, but the available models (and their token caps) only exist at runtime.

This PR adds an additive, back-compat maxRef option that lets the slider read its max from another form field at render time.

Changes

• form-schema.ts — Adds FieldRef interface and SliderFieldMetadata.maxRef?: FieldRef. Existing static max?: number is untouched, so consumers using the plain numeric form keep working with no migration.
• field-renderer.tsx — Extracts the case 'slider' body into a SliderField sub-component (slider needs hooks now). It calls useFormContext().watch(maxRef.fromField) and resolves max as: watched value if finite and positive → maxRef.fallback → static max → 100. If the resolved max drops below the current form value (e.g. user switches to a model with a lower cap), the value is clamped via onChange.
• field-renderer.test.tsx — 6 new tests covering static max, default fallback, maxRef resolution, watched-field-missing fallback, watched-field-non-numeric fallback, and maxRef precedence over static max.

Usage

{
  name: 'inputs.maxTokenPerResponse',
  type: 'slider',
  label: 'Max. tokens per response',
  min: 0,
  step: 1,
  // Watches `inputs.modelMaxTokens` — caller wires this hidden field via
  // setValue() whenever the model picker selection changes.
  maxRef: { fromField: 'inputs.modelMaxTokens', fallback: 16384 },
}

Test plan

• pnpm exec tsc --noEmit — clean
• pnpm test (apollo-wind) — 909 passed (was 903; +6 new)
• pnpm lint — no new diagnostics introduced
• Reviewer sanity check: static max: 100 slider still renders identically (covered by existing tests but worth a manual eyeball in Storybook)

[david-rios-uipath]

a couple nits