refactor(ui): adjust global navigation bar style (#13419)

### What problem does this PR solve?

Renovate global navigation bar, align styles to the design.
(May causes minor layout issues in sub-pages, will check and fix soon)

### Type of change

- [x] Refactoring

web/src/pages/agents/agent-templates.tsx

@@ -1,12 +1,3 @@
-import { PageHeader } from '@/components/page-header';
-import {
-  Breadcrumb,
-  BreadcrumbItem,
-  BreadcrumbLink,
-  BreadcrumbList,
-  BreadcrumbPage,
-  BreadcrumbSeparator,
-} from '@/components/ui/breadcrumb';
 import { useSetModalState } from '@/hooks/common-hooks';
 import { useNavigatePage } from '@/hooks/logic-hooks/navigate-hooks';
 import { useFetchAgentTemplates, useSetAgent } from '@/hooks/use-agent-request';
@@ -15,14 +6,11 @@ import { CardContainer } from '@/components/card-container';
 import { AgentCategory } from '@/constants/agent';
 import { IFlowTemplate } from '@/interfaces/database/agent';
 import { useCallback, useEffect, useMemo, useState } from 'react';
-import { useTranslation } from 'react-i18next';
 import { CreateAgentDialog } from './create-agent-dialog';
 import { TemplateCard } from './template-card';
 import { MenuItemKey, SideBar } from './template-sidebar';
 
 export default function AgentTemplates() {
-  const { navigateToAgents } = useNavigatePage();
-  const { t } = useTranslation();
   const list = useFetchAgentTemplates();
   const { loading, setAgent } = useSetAgent();
   const [templateList, setTemplateList] = useState<IFlowTemplate[]>([]);
@@ -99,21 +87,6 @@ export default function AgentTemplates() {
 
   return (
     <section>
-      <PageHeader>
-        <Breadcrumb>
-          <BreadcrumbList>
-            <BreadcrumbItem>
-              <BreadcrumbLink onClick={navigateToAgents}>
-                {t('flow.agent')}
-              </BreadcrumbLink>
-            </BreadcrumbItem>
-            <BreadcrumbSeparator />
-            <BreadcrumbItem>
-              <BreadcrumbPage>{t('flow.createGraph')}</BreadcrumbPage>
-            </BreadcrumbItem>
-          </BreadcrumbList>
-        </Breadcrumb>
-      </PageHeader>
       <div className="flex flex-1 h-dvh">
         <SideBar
           change={handleSiderBarChange}