♻️ refactor: Replace fontSize Recoil atom with Jotai (#10171)

* fix: reapply chat font size on load

* refactor: streamline font size handling in localStorage

* fix: update matchMedia mock to accurately reflect desktop and touchscreen capabilities

* refactor: implement Jotai for font size management and initialize on app load

- Replaced Recoil with Jotai for font size state management across components.
- Added a new `fontSize` atom to handle font size changes and persist them in localStorage.
- Implemented `initializeFontSize` function to apply saved font size on app load.
- Updated relevant components to utilize the new font size atom.

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Co-authored-by: ddooochii <ddooochii@gmail.com>
Co-authored-by: Danny Avila <danny@librechat.ai>

client/src/store/settings.ts

@@ -21,7 +21,6 @@ const localStorageAtoms = {
   // General settings
   autoScroll: atomWithLocalStorage('autoScroll', false),
   hideSidePanel: atomWithLocalStorage('hideSidePanel', false),
-  fontSize: atomWithLocalStorage('fontSize', 'text-base'),
   enableUserMsgMarkdown: atomWithLocalStorage<boolean>(
     LocalStorageKeys.ENABLE_USER_MSG_MARKDOWN,
     true,