fix: unify ai header action button style

- Changed icon classes in ChatHeader and ChatMoreDropdown to improve visual consistency and styling.
- Updated icons to use new size and opacity classes for better integration with the overall UI design.

Signed-off-by: Innei <tukon479@gmail.com>

apps/desktop/layer/renderer/src/modules/app-layout/ai/components/ChatHeader.tsx

@@ -62,11 +62,11 @@ export const ChatHeader = () => {
         {/* Right side - Actions */}
         <div className="flex items-center gap-2">
           <ActionButton tooltip="New Chat" onClick={handleNewChatClick}>
-            <i className="i-mgc-add-cute-re text-base" />
+            <i className="i-mgc-add-cute-re size-5 opacity-80" />
           </ActionButton>
 
           <ActionButton tooltip="AI Settings" onClick={() => settingModalPresent("ai")}>
-            <i className="i-mgc-user-setting-cute-re text-base" />
+            <i className="i-mgc-user-setting-cute-re size-5 opacity-80" />
           </ActionButton>
 
           <ChatMoreDropdown />

apps/desktop/layer/renderer/src/modules/app-layout/ai/components/ChatMoreDropdown.tsx

@@ -96,7 +96,7 @@ export const ChatMoreDropdown = () => {
     <DropdownMenu onOpenChange={handleDropdownOpen}>
       <DropdownMenuTrigger asChild>
         <ActionButton tooltip="More">
-          <i className="i-mgc-more-1-cute-re text-base" />
+          <i className="i-mingcute-more-1-fill size-5 opacity-80" />
         </ActionButton>
       </DropdownMenuTrigger>
       <DropdownMenuContent align="end" className="w-56">