Add changesets for useDefinition migration and cleanup

Signed-off-by: Johan Persson <johanopersson@gmail.com>

.changeset/calm-vans-play.md

@@ -0,0 +1,7 @@
+---
+'@backstage/ui': patch
+---
+
+Migrated all components from `useStyles` to `useDefinition` hook. Exported `OwnProps` types for each component, enabling better type composition for consumers.
+
+**Affected components:** Avatar, Checkbox, Container, Dialog, FieldError, FieldLabel, Flex, FullPage, Grid, HeaderPage, Link, Menu, PasswordField, PluginHeader, Popover, RadioGroup, SearchField, Select, Skeleton, Switch, Table, TablePagination, Tabs, TagGroup, Text, TextField, ToggleButton, ToggleButtonGroup, Tooltip, VisuallyHidden

.changeset/heavy-baths-mix.md

@@ -0,0 +1,7 @@
+---
+'@backstage/ui': patch
+---
+
+Fixed Link variant default from `'body'` to `'body-medium'` to match actual CSS selectors. The previous default did not correspond to a valid variant value.
+
+**Affected components:** Link

.changeset/lucky-baboons-follow.md

@@ -0,0 +1,15 @@
+---
+'@backstage/ui': minor
+---
+
+**BREAKING**: Removed deprecated types `ComponentDefinition`, `ClassNamesMap`, `DataAttributeValues`, and `DataAttributesMap` from the public API. These were internal styling infrastructure types that have been replaced by the `defineComponent` system.
+
+**Migration:**
+
+Remove any direct usage of these types. Component definitions now use `defineComponent()` and their shapes are not part of the public API contract.
+
+```diff
+- import type { ComponentDefinition, ClassNamesMap } from '@backstage/ui';
+```
+
+If you were reading `definition.dataAttributes`, use `definition.propDefs` instead — props with `dataAttribute: true` in `propDefs` are the equivalent.

.changeset/major-jeans-repair.md

@@ -1,7 +0,0 @@
----
-'@backstage/ui': patch
----
-
-Migrated Avatar, Checkbox, Container, FieldError, FieldLabel, Link, and Skeleton components from `useStyles` to `useDefinition` hook. Exported `OwnProps` types for each migrated component. Fixed Link variant default from `'body'` to `'body-medium'` to match actual CSS selectors.
-
-**Affected components:** Avatar, Checkbox, Container, FieldError, FieldLabel, Link, Skeleton

packages/ui/src/components/VisuallyHidden/definition.ts

@@ -22,8 +22,8 @@ import styles from './VisuallyHidden.module.css';
  * Component definition for VisuallyHidden
  * @public
  */
-export const VisuallyHiddenDefinition = defineComponent<VisuallyHiddenOwnProps>()(
-  {
+export const VisuallyHiddenDefinition =
+  defineComponent<VisuallyHiddenOwnProps>()({
     styles,
     classNames: {
       root: 'bui-VisuallyHidden',
@@ -31,5 +31,4 @@ export const VisuallyHiddenDefinition = defineComponent<VisuallyHiddenOwnProps>(
     propDefs: {
       className: {},
     },
-  },
-);
+  });