[CLAUDE] FE: PE detail flat layout — Panel 2 gop 3 section, Panel 3 them approvals + history

User request: 'cho tat ca cai nay the hien tren dung 1 man hinh nhe, cai
duyet va lich su thi dua sang panel 3'.

Panel 2 (PeDetailTabs): truoc 5 tab (Info/NCC/Items/Approvals/History).
Sau bo tabs, flat render 3 section stack doc voi divider + title uppercase:
  Thong tin → NCC tham gia (N) → Hang muc + Bao gia (N)

Panel 3 (PeWorkflowPanel): truoc chi workflow timeline + transition btn.
Sau them 2 section ben duoi:
  Workflow timeline → Lich su duyet (PeApprovalsSection) → Lich su thay doi
  (PeHistorySection)

Export PeApprovalsSection + PeHistorySection tu PeDetailTabs — reuse
ApprovalsTab + HistoryTab logic cu, wrap them <h3> section title.

Dong bo ca fe-admin + fe-user (copy identical file).

fe-admin/src/components/pe/PeDetailTabs.tsx

@@ -1,6 +1,7 @@
-// Detail tabs cho 1 phiếu Duyệt NCC: Thông tin / NCC / Hạng mục + Báo giá /
-// Duyệt / Lịch sử. Inline action dialog để add NCC, add Detail, upsert Quote,
-// select winner.
+// Detail content cho 1 phiếu Duyệt NCC. Flat render (no tabs): Thông tin +
+// NCC + Hạng mục + Báo giá stack vertically trong 1 màn hình.
+// Duyệt history + Lịch sử thay đổi → moved to Panel 3 (xem PeWorkflowPanel
+// → PeApprovalsSection + PeHistorySection).
 import { useState } from 'react'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { useNavigate } from 'react-router-dom'
@@ -27,10 +28,10 @@ import {
 } from '@/types/purchaseEvaluation'
 import type { Supplier } from '@/types/master'
 
-type TabKey = 'info' | 'suppliers' | 'items' | 'approvals' | 'history'
-
 const fmtMoney = (v: number) => v.toLocaleString('vi-VN')
 
+// Main detail content — flat render 3 section không tabs.
+// Tên giữ PeDetailTabs để không break callsite (rename gây churn).
 export function PeDetailTabs({
   evaluation,
   onBack,
@@ -40,7 +41,6 @@ export function PeDetailTabs({
   onBack: () => void
   onDelete: () => void
 }) {
-  const [tab, setTab] = useState<TabKey>('info')
   const navigate = useNavigate()
   const isDraft = evaluation.phase === PurchaseEvaluationPhase.DangSoanThao
 
@@ -83,42 +83,50 @@ export function PeDetailTabs({
         </div>
       </div>
 
-      <nav className="flex gap-1 border-b border-slate-200 px-3 pt-2">
-        {(
-          [
-            ['info', 'Thông tin'],
-            ['suppliers', `NCC (${evaluation.suppliers.length})`],
-            ['items', `Hạng mục (${evaluation.details.length})`],
-            ['approvals', `Duyệt (${evaluation.approvals.length})`],
-            ['history', 'Lịch sử'],
-          ] as const
-        ).map(([k, lbl]) => (
-          <button
-            key={k}
-            onClick={() => setTab(k)}
-            className={cn(
-              'rounded-t-md border-b-2 px-3 py-1.5 text-xs font-medium transition',
-              tab === k
-                ? 'border-brand-500 text-brand-700'
-                : 'border-transparent text-slate-500 hover:text-slate-700',
-            )}
-          >
-            {lbl}
-          </button>
-        ))}
-      </nav>
-
-      <div className="p-5">
-        {tab === 'info' && <InfoTab ev={evaluation} />}
-        {tab === 'suppliers' && <SuppliersTab ev={evaluation} />}
-        {tab === 'items' && <ItemsTab ev={evaluation} />}
-        {tab === 'approvals' && <ApprovalsTab ev={evaluation} />}
-        {tab === 'history' && <HistoryTab ev={evaluation} />}
+      <div className="divide-y divide-slate-200">
+        <Section title="Thông tin">
+          <InfoTab ev={evaluation} />
+        </Section>
+        <Section title={`NCC tham gia (${evaluation.suppliers.length})`}>
+          <SuppliersTab ev={evaluation} />
+        </Section>
+        <Section title={`Hạng mục + Báo giá (${evaluation.details.length})`}>
+          <ItemsTab ev={evaluation} />
+        </Section>
       </div>
     </div>
   )
 }
 
+function Section({ title, children }: { title: string; children: React.ReactNode }) {
+  return (
+    <section className="px-5 py-4">
+      <h3 className="mb-3 text-xs font-semibold uppercase tracking-wide text-slate-500">{title}</h3>
+      {children}
+    </section>
+  )
+}
+
+// ===== Exports cho Panel 3 — Approvals history + Changelog =====
+
+export function PeApprovalsSection({ ev }: { ev: PeDetailBundle }) {
+  return (
+    <div>
+      <h3 className="mb-2 text-sm font-semibold text-slate-900">Lịch sử duyệt ({ev.approvals.length})</h3>
+      <ApprovalsTab ev={ev} />
+    </div>
+  )
+}
+
+export function PeHistorySection({ ev }: { ev: PeDetailBundle }) {
+  return (
+    <div>
+      <h3 className="mb-2 text-sm font-semibold text-slate-900">Lịch sử thay đổi</h3>
+      <HistoryTab ev={ev} />
+    </div>
+  )
+}
+
 // ===== Tab: Thông tin =====
 function InfoTab({ ev }: { ev: PeDetailBundle }) {
   const canCreateContract = ev.phase === PurchaseEvaluationPhase.DaDuyet && !ev.contractId && ev.selectedSupplierId