feat(i18n): add Indonesian (Bahasa Indonesia) language support (#1399)

- Add 'id' to Language type in translations.ts
- Add ~1000 Indonesian translation keys covering all UI sections
- Update LanguageContext to persist 'id' in localStorage
- Add ID button to Header.tsx language toggle
- Add �� option to HeaderBar.tsx desktop dropdown and mobile toggle
- Add Indonesian translations to inline text objects in
  LoginRequiredOverlay, StrategyMarketPage, PositionHistory

Closes #XX

web/src/components/Header.tsx

@@ -57,6 +57,17 @@ export function Header({ simple = false }: HeaderProps) {
             >
               EN
             </button>
+            <button
+              onClick={() => setLanguage('id')}
+              className="px-3 py-1.5 rounded text-xs font-semibold transition-all"
+              style={
+                language === 'id'
+                  ? { background: '#F0B90B', color: '#000' }
+                  : { background: 'transparent', color: '#848E9C' }
+              }
+            >
+              ID
+            </button>
           </div>
         </div>
       </Container>

web/src/components/HeaderBar.tsx

@@ -99,8 +99,8 @@ export default function HeaderBar({
             {(() => {
               // Define all navigation tabs
               const navTabs: { page: Page; path: string; label: string; requiresAuth: boolean }[] = [
-                { page: 'data', path: '/data', label: language === 'zh' ? '数据' : 'Data', requiresAuth: false },
+                { page: 'data', path: '/data', label: language === 'zh' ? '数据' : language === 'id' ? 'Data' : 'Data', requiresAuth: false },
-                { page: 'strategy-market', path: '/strategy-market', label: language === 'zh' ? '策略市场' : 'Market', requiresAuth: true },
+                { page: 'strategy-market', path: '/strategy-market', label: language === 'zh' ? '策略市场' : language === 'id' ? 'Pasar' : 'Market', requiresAuth: true },
                 { page: 'traders', path: '/traders', label: t('configNav', language), requiresAuth: true },
                 { page: 'trader', path: '/dashboard', label: t('dashboardNav', language), requiresAuth: true },
                 { page: 'strategy', path: '/strategy', label: t('strategyNav', language), requiresAuth: true },
@@ -259,7 +259,7 @@ export default function HeaderBar({
                 className="flex items-center gap-2 px-3 py-2 rounded transition-colors text-nofx-text-muted hover:bg-white/5"
               >
                 <span className="text-lg">
-                  {language === 'zh' ? '🇨🇳' : '🇺🇸'}
+                  {language === 'zh' ? '🇨🇳' : language === 'id' ? '🇮🇩' : '🇺🇸'}
                 </span>
                 <ChevronDown className="w-4 h-4" />
               </button>
@@ -288,6 +288,17 @@ export default function HeaderBar({
                     <span className="text-base">🇺🇸</span>
                     <span className="text-sm">English</span>
                   </button>
+                  <button
+                    onClick={() => {
+                      onLanguageChange?.('id')
+                      setLanguageDropdownOpen(false)
+                    }}
+                    className={`w-full flex items-center gap-2 px-3 py-2 transition-colors text-nofx-text-muted hover:text-white
+                      ${language === 'id' ? 'bg-nofx-gold/10' : 'hover:bg-white/5'}`}
+                  >
+                    <span className="text-base">🇮🇩</span>
+                    <span className="text-sm">Bahasa</span>
+                  </button>
                 </div>
               )}
             </div>
@@ -329,8 +340,8 @@ export default function HeaderBar({
               <div className="flex flex-col gap-6 mb-12">
                 {(() => {
                   const navTabs: { page: Page; path: string; label: string; requiresAuth: boolean }[] = [
-                    { page: 'data', path: '/data', label: language === 'zh' ? '数据' : 'Data', requiresAuth: false },
+                    { page: 'data', path: '/data', label: language === 'zh' ? '数据' : language === 'id' ? 'Data' : 'Data', requiresAuth: false },
-                    { page: 'strategy-market', path: '/strategy-market', label: language === 'zh' ? '策略市场' : 'Market', requiresAuth: true },
+                    { page: 'strategy-market', path: '/strategy-market', label: language === 'zh' ? '策略市场' : language === 'id' ? 'Pasar' : 'Market', requiresAuth: true },
                     { page: 'traders', path: '/traders', label: t('configNav', language), requiresAuth: true },
                     { page: 'trader', path: '/dashboard', label: t('dashboardNav', language), requiresAuth: true },
                     { page: 'strategy', path: '/strategy', label: t('strategyNav', language), requiresAuth: true },
@@ -429,7 +440,7 @@ export default function HeaderBar({
                 <div className="grid grid-cols-2 gap-4">
                   {/* Lang Switcher */}
                   <div className="flex bg-zinc-900 rounded-lg p-1 border border-zinc-800">
-                    {['zh', 'en'].map((lang) => (
+                    {['zh', 'en', 'id'].map((lang) => (
                       <button
                         key={lang}
                         onClick={() => {
@@ -441,7 +452,7 @@ export default function HeaderBar({
                           : 'text-zinc-500'
                           }`}
                       >
-                        {lang === 'zh' ? 'CN' : 'EN'}
+                        {lang === 'zh' ? 'CN' : lang === 'id' ? 'ID' : 'EN'}
                       </button>
                     ))}
                   </div>

web/src/components/LoginRequiredOverlay.tsx

@@ -40,6 +40,20 @@ export function LoginRequiredOverlay({ isOpen, onClose, featureName }: LoginRequ
       login: 'EXECUTE LOGIN',
       register: 'REGISTER NEW ID',
       later: 'ABORT'
+    },
+    id: {
+      title: 'AKSES SISTEM DITOLAK',
+      subtitle: featureName ? `Modul "${featureName}" memerlukan hak akses lebih tinggi` : 'Otorisasi diperlukan untuk modul ini',
+      description: 'Inisialisasi protokol autentikasi untuk membuka kemampuan sistem penuh: konfigurasi Trader AI, aliran data Pasar Strategi, dan inti Simulasi Backtest.',
+      benefits: [
+        'Kontrol Trader AI',
+        'Pasar Strategi HFT',
+        'Mesin Backtest Historis',
+        'Visualisasi Sistem Penuh'
+      ],
+      login: 'JALANKAN LOGIN',
+      register: 'DAFTAR ID BARU',
+      later: 'BATALKAN'
     }
   }
 

web/src/components/PositionHistory.tsx

@@ -1,7 +1,7 @@
 import { useState, useEffect, useMemo } from 'react'
 import { api } from '../lib/api'
 import { useLanguage } from '../contexts/LanguageContext'
-import { t } from '../i18n/translations'
+import { t, type Language } from '../i18n/translations'
 import { MetricTooltip } from './MetricTooltip'
 import { formatPrice, formatQuantity } from '../utils/format'
 import type {
@@ -152,7 +152,7 @@ function SymbolStatsRow({ stat }: { stat: SymbolStats }) {
 }
 
 // Direction Stats Card
-function DirectionStatsCard({ stat, language }: { stat: DirectionStats; language: 'en' | 'zh' }) {
+function DirectionStatsCard({ stat, language }: { stat: DirectionStats; language: Language }) {
   const isLong = (stat.side || '').toLowerCase() === 'long'
   const iconColor = isLong ? '#0ECB81' : '#F6465D'
   const totalPnl = stat.total_pnl || 0

web/src/contexts/LanguageContext.tsx

@@ -14,7 +14,7 @@ export function LanguageProvider({ children }: { children: ReactNode }) {
   // Initialize language from localStorage or default to English
   const [language, setLanguage] = useState<Language>(() => {
     const saved = localStorage.getItem('language')
-    return saved === 'en' || saved === 'zh' ? saved : 'en'
+    return saved === 'en' || saved === 'zh' || saved === 'id' ? saved : 'en'
   })
 
   // Save language to localStorage whenever it changes

web/src/pages/StrategyMarketPage.tsx

@@ -158,6 +158,32 @@ export function StrategyMarketPage() {
       shareYours: 'UPLOAD_STRATEGY',
       makePublic: 'PUBLISH',
       loading: 'INITIALIZING...'
+    },
+    id: {
+      title: 'PASAR STRATEGI',
+      subtitle: 'DATABASE STRATEGI GLOBAL',
+      description: 'Temukan, analisis, dan kloning algoritma trading berperforma tinggi',
+      search: 'CARI PARAMETER...',
+      all: 'SEMUA PROTOKOL',
+      popular: 'TREN',
+      recent: 'TERBARU',
+      myStrategies: 'PERPUSTAKAAN SAYA',
+      noStrategies: 'TIDAK ADA SINYAL',
+      noStrategiesDesc: 'Tidak ada sinyal strategis terdeteksi pada frekuensi ini',
+      author: 'OPERATOR',
+      createdAt: 'TIMESTAMP',
+      viewConfig: 'DEKRIPSI CONFIG',
+      hideConfig: 'ENKRIPSI',
+      copyConfig: 'KLON CONFIG',
+      copied: 'DISALIN',
+      configHidden: 'TERENKRIPSI',
+      configHiddenDesc: 'Parameter konfigurasi terenkripsi',
+      indicators: 'INDIKATOR',
+      maxPositions: 'BATAS_POS',
+      maxLeverage: 'LEV_MAKS',
+      shareYours: 'UNGGAH_STRATEGI',
+      makePublic: 'PUBLIKASI',
+      loading: 'MENGINISIALISASI...'
     }
   }