fix: remove unwanted toolbar bar above mail columns

frontend/src/pages/Mail.tsx

@@ -16,8 +16,6 @@ import { MailFolderTree } from '@/components/mail/MailFolderTree';
 import { MailList } from '@/components/mail/MailList';
 import { MailDetail } from '@/components/mail/MailDetail';
 import { ComposeModal, type ComposeMode } from '@/components/mail/ComposeModal';
-import { SharedMailboxSelector } from '@/components/mail/SharedMailboxSelector';
-import { MailSearchBar } from '@/components/mail/MailSearchBar';
 import { usePluginToolbarStore } from '@/store/pluginToolbarStore';
 import {
   fetchAccounts,
@@ -703,22 +701,6 @@ export function MailPage() {
         </div>
       )}
 
-      {/* Mail toolbar */}
-      <div className="flex items-center gap-2 px-3 py-2 border-b border-secondary-200 bg-white">
-        <Button onClick={handleCompose} size="sm" data-testid="compose-btn">
-          {t('mail.compose')}
-        </Button>
-        <MailSearchBar
-          onSearch={(q) => { setSearchQuery(q); setMailsPage(1); }}
-          value={searchQuery}
-        />
-        <SharedMailboxSelector
-          accounts={accounts.filter(a => a.is_shared)}
-          selectedAccountId={selectedAccountId}
-          onSelect={(id) => { setSelectedAccountId(id); setSelectedFolderId(null); }}
-        />
-      </div>
-
       {/* Desktop: three-pane layout with resizable panels */}
       <div className="hidden md:flex flex-1 overflow-hidden">
         {/* Folder tree — resizable */}