[Customer account UI extensions 2025-07]: Improved descriptions for "Layout and structure" components

[mcvinci]

This PR:

• Improves JSDoc descriptions for layout and structure components in the 2025-07 checkout and customer account surfaces to align with admin UI extensions documentation style — declarative opening sentences, bulleted value descriptions for enum/union props, and inline "Learn more about" links replacing @see tags.
• Adds missing type-level and interface-level JSDoc across shared.ts for all public types referenced by layout components (Breakpoint, Display, CornerRadius, NonPresentationalAccessibilityRole, ViewLikeAccessibilityRole, Opacity, GridItemSize, Columns, Rows, Visibility, etc.) and their container interfaces (BackgroundProps, BorderProps, CornerProps, SizingProps, SpacingProps, VisibilityProps).
• Removes duplicate bullet-point descriptions from props that already reference a named type (e.g., background, backgroundFit, display on View, visibility) — values are now documented once on the type, not on both the type and the prop.
• Adds prop-level descriptions for StylesBaseConditions, StylesConditions, InteractiveConditions, and ViewportInlineSize in the StyleHelper types so the docs page renders descriptions for focus, hover, resolution, and viewportInlineSize.
• Adds full property-level descriptions for Docs_Page_Button_PrimaryAction and Docs_Page_Button_SecondaryAction in the customer account API docs.
• Fixes swapped cover/contain member descriptions on the Fit type.
• Replaces imperative phrasing ("Sets the…", "Adjust the…") with declarative noun phrases across all layout component files.
• Relates to https://github.com/shop/world/pull/579467
• Partially closes https://github.com/shop/issues-learn/issues/1008

[github-actions]

🚨🚨🚨 Docs migration in progress 🚨🚨🚨

We are actively migrating UI extension reference docs to MDX in the areas/platforms/shopify-dev zone of the monorepo. This impacts docs for the following surfaces:

• Admin UI extensions
• App Home
• Checkout UI extensions
• Customer account UI extensions
• POS UI extensions

During this migration, please be aware of the following:

.doc.ts files are being deprecated. Changes to .doc.ts files in this repo will not be reflected in the new MDX-based docs. If you need to update docs for a reference that has already been migrated, make your changes directly in the areas/platforms/shopify-dev zone of the monorepo instead.

Doc comments in .ts source files (the comment blocks above types and functions) are also affected. Generating docs from these comments currently requires a newer version of the @shopify/generate-docs library that isn't yet available. Updates to doc comments may not produce the expected output until the migration is complete.

Examples that previously lived in this repo are being moved to the areas/platforms/shopify-dev zone of the monorepo and should be authored there going forward.

What should I do?

• If your PR includes changes to .doc.ts files, doc comments, or examples, please reach out to us in #devtools-proj-templated-refs so we can help ensure your updates are captured correctly.
• If your PR is limited to source code changes (non-docs), you can ignore this notice.

Thanks for your patience while we complete the migration! 🙏

[github-actions]

We detected some changes in packages/*/package.json or packages/*/src, and there are no updates in the .changeset directory. If the changes are user-facing and should cause a version bump, run yarn changeset to track your changes and include them in the next release CHANGELOG. If you are making simple updates to repo configuration, examples, or documentation, you do not need to add a changeset.