🔧 fix+chore: Resolve Overflow in Settings Modal & Upgrade to Headless UI 2.0 (#2661)

* fix: dropdown overflow

* fix: make dropdown work on mobile

* feat: update headlessui to 2.0 and use portal

* feat: rewrite modal using headlessui

* fix: applying of maxHeight

* fix: optimize backdrop for dark mode

* fix: rendering dropdown width

* feat: match small screen layout to radix-ui dialog

* revert: mobile modifications

* fix: modal animations

* fix: z-index

* chore: Migrate from HeadlessUI 1.0 to 2.0

* fix: h2 nesting

* fix: use lighter border for PopoverButtons

* feat: Move modal to the top if using a small screen

* fix: mobile position

* fix: frontend tests

* feat: use row layout in mobile instead of col

* fix: remove config path from tsconfig

* fix: fix dropdown tests (gpt4o ftw!)

* feat: Upgrade to latest headlessui version

* fix:test1

* fix: ThemeSelector test

* fix: re-add speech tab

* style: use pl and pr-3

* fix: speech tab dropdowns

* style: use maxHeight for language

* feat: convert DropdownNoState to v2.0

* fix: use v2 params for voiceDropdown

* style: reduce maxHeight for VoiceDropdown and set fixed width

* chore: rebuild package-lock

* style(fix): copy over the same styles for the settingsTab

* style(fix): use -top-1 for speech tabs

* style(fix): use max-w-[400px]

---------

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

client/src/components/Nav/SettingsTabs/General/General.tsx

@@ -34,9 +34,8 @@ export const ThemeSelector = ({
         value={theme}
         onChange={onChange}
         options={themeOptions}
-        width={180}
-        position={'left'}
-        maxHeight="200px"
+        sizeClasses="w-[220px]"
+        anchor="bottom start"
         testId="theme-selector"
       />
     </div>
@@ -111,8 +110,8 @@ export const LangSelector = ({
       <Dropdown
         value={langcode}
         onChange={onChange}
-        position={'left'}
-        maxHeight="271px"
+        sizeClasses="[--anchor-max-height:256px]"
+        anchor="bottom start"
         options={languageOptions}
       />
     </div>