chore(deps): update devdependency @nuxt/ui to v4

Coming soon: The Renovate bot (GitHub App) will be renamed to Mend. PRs from Renovate will soon appear from 'Mend'. Learn more [here](https://redirect.github.com/renovatebot/renovate/discussions/37842). This PR contains the following updates: | Package | Change | Age | Confidence | |---|---|---|---| | [@nuxt/ui](https://ui.nuxt.com) ([source](https://redirect.github.com/nuxt/ui)) | [`^3.3.5` -> `^4.0.0`](https://renovatebot.com/diffs/npm/@nuxt%2fui/3.3.5/4.0.0) | [](https://docs.renovatebot.com/merge-confidence/) | [](https://docs.renovatebot.com/merge-confidence/) | --- ### Release Notes <details> <summary>nuxt/ui (@&#8203;nuxt/ui)</summary> ### [`v4.0.0`](https://redirect.github.com/nuxt/ui/blob/HEAD/CHANGELOG.md#400-2025-09-23) [Compare Source](https://redirect.github.com/nuxt/ui/compare/v3.3.5...v4.0.0) </details> --- ### Configuration 📅 **Schedule**: Branch creation - "on Monday" (UTC), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box --- This PR was generated by [Mend Renovate](https://mend.io/renovate/). View the [repository job log](https://developer.mend.io/github/nuxt-modules/leaflet). <!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0MS4xMzEuOSIsInVwZGF0ZWRJblZlciI6IjQxLjEzMS45IiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6W119-->