docs: add max_preset property to Preset feature

[chrismerck]

Summary

• Adds max_preset read-only property to the Preset feature
• Updates Preset() action to document optional integer argument (1..max_preset)
• Documents default behavior: middle preset used when argument omitted

Context

Spec: docs/superpowers/specs/2026-03-30-multiple-preset-support-design.md in eng meta-repo.

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[OlibraBot]

The rendered doc is at: https://bond-api-docs.s3.amazonaws.com/merck-max-preset-local.html

[chrismerck]

Trigger for this is a Dendo customer who wants to send their shades to "Preset B" (preset number 3) via Schedule, and I realize that although this is possible through the API, it was not documented and therefore not supported via the app interface.