[2026-04] Clarify NumberField and MoneyField event documentation

[johnnie-chen]

Background

NumberField and MoneyField event descriptions omit that stepping a value fires both input and change. This documents the existing shared Checkout/Customer Accounts behavior for API version 2026-04.

Backport of #4703. Source documentation change: https://meteorite.shopify.io/repos/shop/world/pulls/2079504

Solution

Clarify blur/Enter commitment and per-step input and change events. NumberField covers increment/decrement controls and arrow keys; MoneyField covers arrow keys. Update the two declaration comments and generated reference data for both surfaces. There are no runtime or API-signature changes.

Generated output is limited to the relevant event descriptions; unrelated generator drift is excluded.

🎩

• yarn docs:checkout 2026-04 and yarn docs:customer-account 2026-04 completed.
• Confirmed that each generated JSON changes only the two event interfaces and that declaration signatures are unchanged.
• yarn lint, yarn build, yarn type-check, and git diff --check passed. Lint ran before build to avoid the existing generated-entrypoint ignore-pattern issue.
• The identical descriptions were visually verified on all four 2026-07 local pages in [2026-07] Clarify NumberField and MoneyField event documentation #4703. This backport's generated entries were checked structurally; its pages have not been separately previewed in a browser.

Checklist

• I have 🎩'd these changes
• I have updated relevant documentation