fix: align sidebar toggle bottom border with navbar (#1864)

[x15sr71]

PR Fixes:

1. Fixed incorrect padding for sidebar toggle to visually align with navbar border.
2. Ensured the fix works consistently in both collapsed and expanded sidebar states for visual consistency.

Resolves #[1864]

Checklist before requesting a review

• [x] I have performed a self-review of my code
• [x] I assure there is no similar/duplicate pull request regarding same issue

[x15sr71]

One CI test is failing because it runs pnpm run format:check, which requires prettier-plugin-tailwindcss. However, this plugin isn't listed as a dev dependency in the cms/package.json. Should we add it to devDependencies, or update the CI/config to avoid requiring it?