feat: translate all UI strings to English for international release

Complete French→English translation across all frontend pages and backend
services — every label, button, header, empty state, toast, and nav item
is now in English. Build verified clean (tsc + vite). No i18n library
added; direct string replacement throughout.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/pages/Analytics.tsx

@@ -8,8 +8,8 @@ function ReliabilityTable({ data }: { data: any[] }) {
     return (
       <div className="card text-center py-10 text-slate-500">
         <BarChart2 className="w-8 h-8 mx-auto mb-2 opacity-20" />
-        <div>Aucune donnée de fiabilité</div>
-        <div className="text-xs mt-1">Les données apparaissent après 3+ trades matures (≥35% de l'horizon écoulé) par pattern</div>
+        <div>No reliability data</div>
+        <div className="text-xs mt-1">Data appears after 3+ mature trades (≥35% of horizon elapsed) per pattern</div>
       </div>
     )
   }
@@ -22,10 +22,10 @@ function ReliabilityTable({ data }: { data: any[] }) {
             <th className="text-left py-2 pr-3 font-medium">Pattern</th>
             <th className="text-right py-2 px-2 font-medium">Trades</th>
             <th className="text-right py-2 px-2 font-medium">Win Rate</th>
-            <th className="text-right py-2 px-2 font-medium">PnL moyen</th>
+            <th className="text-right py-2 px-2 font-medium">Avg PnL</th>
             <th className="text-right py-2 px-2 font-medium">Max gain</th>
-            <th className="text-right py-2 px-2 font-medium">Max perte</th>
-            <th className="text-right py-2 px-2 font-medium">Score fiabilité</th>
+            <th className="text-right py-2 px-2 font-medium">Max loss</th>
+            <th className="text-right py-2 px-2 font-medium">Reliability score</th>
           </tr>
         </thead>
         <tbody className="divide-y divide-slate-800/50">
@@ -69,8 +69,8 @@ function CalibrationSection({ data }: { data: any }) {
     return (
       <div className="card text-center py-10 text-slate-500">
         <Target className="w-8 h-8 mx-auto mb-2 opacity-20" />
-        <div>Pas encore de données de calibration</div>
-        <div className="text-xs mt-1">Nécessite des trades matures avec probabilité stockée vs résultat réalisé</div>
+        <div>No calibration data yet</div>
+        <div className="text-xs mt-1">Requires mature trades with stored probability vs realized outcome</div>
       </div>
     )
   }
@@ -84,31 +84,31 @@ function CalibrationSection({ data }: { data: any }) {
         <div className="card text-center">
           <div className={clsx('text-2xl font-bold font-mono', brierColor)}>{brier_score?.toFixed(3) ?? '—'}</div>
           <div className="text-xs text-slate-500 mt-1">Brier Score</div>
-          <div className="text-xs text-slate-600">(0 = parfait, 1 = nul)</div>
+          <div className="text-xs text-slate-600">(0 = perfect, 1 = null)</div>
         </div>
         <div className="card text-center">
           <div className="text-2xl font-bold text-white">{sample_size}</div>
-          <div className="text-xs text-slate-500 mt-1">Trades analysés</div>
+          <div className="text-xs text-slate-500 mt-1">Trades analyzed</div>
         </div>
         <div className="card text-center">
           <div className={clsx('text-sm font-bold mt-1', brierColor)}>{interpretation ?? '—'}</div>
-          <div className="text-xs text-slate-500 mt-1">Interprétation</div>
+          <div className="text-xs text-slate-500 mt-1">Interpretation</div>
         </div>
       </div>
 
       {/* Calibration buckets */}
       {buckets && buckets.length > 0 && (
         <div>
-          <div className="text-xs text-slate-500 mb-2 font-medium">Calibration par décile (prédit vs réalisé)</div>
+          <div className="text-xs text-slate-500 mb-2 font-medium">Calibration by decile (predicted vs realized)</div>
           <div className="overflow-x-auto">
             <table className="w-full text-xs">
               <thead>
                 <tr className="text-slate-500 border-b border-slate-700/30">
-                  <th className="text-left py-1.5 pr-3 font-medium">Prob. prédite</th>
-                  <th className="text-right py-1.5 px-2 font-medium">Taux réel</th>
-                  <th className="text-right py-1.5 px-2 font-medium">Biais</th>
+                  <th className="text-left py-1.5 pr-3 font-medium">Predicted prob.</th>
+                  <th className="text-right py-1.5 px-2 font-medium">Actual rate</th>
+                  <th className="text-right py-1.5 px-2 font-medium">Bias</th>
                   <th className="text-right py-1.5 px-2 font-medium">Trades</th>
-                  <th className="py-1.5 pl-3 font-medium">Barre</th>
+                  <th className="py-1.5 pl-3 font-medium">Bar</th>
                 </tr>
               </thead>
               <tbody className="divide-y divide-slate-800/50">
@@ -142,7 +142,7 @@ function CalibrationSection({ data }: { data: any }) {
             </table>
           </div>
           <div className="text-[10px] text-slate-600 mt-2">
-            Barre grise = prob. prédite · Barre colorée = taux réalisé · Vert si réel ≥ prédit, rouge sinon
+            Grey bar = predicted prob. · Colored bar = realized rate · Green if actual ≥ predicted, red otherwise
           </div>
         </div>
       )}
@@ -166,7 +166,7 @@ export default function Analytics() {
           <BarChart2 className="w-5 h-5 text-blue-400" /> Analytics & Calibration
         </h1>
         <p className="text-xs text-slate-500 mt-0.5">
-          Fiabilité historique des patterns · Calibration probabiliste · Brier score
+          Historical pattern reliability · Probabilistic calibration · Brier score
         </p>
       </div>
 
@@ -175,18 +175,18 @@ export default function Analytics() {
         <div className="grid grid-cols-2 gap-4 sm:grid-cols-4">
           <div className="card">
             <div className="text-2xl font-bold text-white font-mono">{reliability.length}</div>
-            <div className="text-xs text-slate-500 mt-1">Patterns avec historique</div>
+            <div className="text-xs text-slate-500 mt-1">Patterns with history</div>
           </div>
           <div className="card">
             <div className="text-2xl font-bold text-white font-mono">
               {reliability.reduce((s: number, r: any) => s + r.trade_count, 0)}
             </div>
-            <div className="text-xs text-slate-500 mt-1">Trades matures analysés</div>
+            <div className="text-xs text-slate-500 mt-1">Mature trades analyzed</div>
           </div>
           {topPatterns[0] && (
             <div className="card border-emerald-700/30">
               <div className="text-xs text-slate-500 mb-1 flex items-center gap-1">
-                <TrendingUp className="w-3 h-3 text-emerald-400" /> Meilleur pattern
+                <TrendingUp className="w-3 h-3 text-emerald-400" /> Best pattern
               </div>
               <div className="text-sm font-semibold text-emerald-400 truncate">{topPatterns[0].pattern_name}</div>
               <div className="text-xs font-mono text-slate-400">{topPatterns[0].win_rate_pct}% WR</div>
@@ -195,7 +195,7 @@ export default function Analytics() {
           {bottomPatterns[0] && (
             <div className="card border-red-700/30">
               <div className="text-xs text-slate-500 mb-1 flex items-center gap-1">
-                <AlertTriangle className="w-3 h-3 text-red-400" /> À éviter
+                <AlertTriangle className="w-3 h-3 text-red-400" /> To avoid
               </div>
               <div className="text-sm font-semibold text-red-400 truncate">{bottomPatterns[0].pattern_name}</div>
               <div className="text-xs font-mono text-slate-400">{bottomPatterns[0].win_rate_pct}% WR</div>
@@ -207,8 +207,8 @@ export default function Analytics() {
       {/* Reliability table */}
       <div className="card">
         <div className="text-sm font-semibold text-white mb-3 flex items-center gap-2">
-          <BarChart2 className="w-4 h-4 text-blue-400" /> Fiabilité par pattern
-          <span className="text-xs text-slate-500 font-normal">(trades ≥35% de l'horizon uniquement)</span>
+          <BarChart2 className="w-4 h-4 text-blue-400" /> Reliability by pattern
+          <span className="text-xs text-slate-500 font-normal">(trades ≥35% of horizon only)</span>
         </div>
         {loadingR ? (
           <div className="space-y-2">{[1,2,3].map(i => <div key={i} className="h-8 bg-dark-700 animate-pulse rounded" />)}</div>
@@ -221,17 +221,17 @@ export default function Analytics() {
       <div className="card">
         <div className="flex items-center justify-between mb-3">
           <div className="text-sm font-semibold text-white flex items-center gap-2">
-            <Target className="w-4 h-4 text-blue-400" /> Calibration probabiliste
+            <Target className="w-4 h-4 text-blue-400" /> Probabilistic calibration
           </div>
           <select
             value={calDays}
             onChange={e => setCalDays(Number(e.target.value))}
             className="bg-dark-700 border border-slate-700 rounded px-2 py-1 text-xs text-slate-300"
           >
-            <option value={90}>90 jours</option>
-            <option value={180}>180 jours</option>
-            <option value={365}>1 an</option>
-            <option value={730}>2 ans</option>
+            <option value={90}>90 days</option>
+            <option value={180}>180 days</option>
+            <option value={365}>1 year</option>
+            <option value={730}>2 years</option>
           </select>
         </div>
         {loadingC ? (