feat: score justification on trade cards

- Add ScorePillars: compact 4-pillar mini-bars always visible under score
  bar (📰/📅/📈/⚖️ with color-coded fill — instant visual of pillar distribution)
- Add ScoreJustification: replaces old per-click BucketBreakdown with full
  text reasoning shown at once — key_catalyst highlighted in yellow callout,
  each pillar shows score + GPT-4o comment + all sub-pillars with comments
- Rename expand button to "↳ Justification du score" for clarity

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

frontend/src/pages/Dashboard.tsx

@@ -53,46 +53,74 @@ function BucketBar({ score, max }: { score: number; max: number }) {
   )
 }
 
-function BucketBreakdown({ buckets }: { buckets: any[] }) {
-  const [openBucket, setOpenBucket] = useState<string | null>(null)
+// Compact 4-pillar mini-bars always visible on card
+function ScorePillars({ buckets }: { buckets: any[] }) {
+  if (!buckets?.length) return null
   return (
-    <div className="space-y-1 text-xs">
+    <div className="grid grid-cols-4 gap-1 mb-2">
       {buckets.map((b: any) => {
         const pct = b.max > 0 ? Math.round((b.score / b.max) * 100) : 0
-        const isOpen = openBucket === b.id
+        const color = pct >= 70 ? 'bg-emerald-500' : pct >= 45 ? 'bg-yellow-500' : 'bg-red-500/70'
         return (
-          <div key={b.id} className="bg-dark-700/60 rounded overflow-hidden">
-            <button
-              className="w-full flex items-center gap-1.5 px-2 py-1.5 hover:bg-dark-600/60 transition-colors text-left"
-              onClick={() => setOpenBucket(isOpen ? null : b.id)}
-            >
-              <span>{BUCKET_ICONS[b.id] ?? '•'}</span>
-              <span className="text-slate-400 flex-1 truncate">{b.label}</span>
+          <div key={b.id} className="flex flex-col items-center gap-0.5">
+            <div className="w-full bg-slate-700/60 rounded-full h-1">
+              <div className={clsx('h-1 rounded-full', color)} style={{ width: `${pct}%` }} />
+            </div>
+            <span className="text-[9px] text-slate-600 truncate w-full text-center leading-none">
+              {BUCKET_ICONS[b.id]} {b.score}/{b.max}
+            </span>
+          </div>
+        )
+      })}
+    </div>
+  )
+}
+
+// Full justification panel — all comments at once, no per-bucket clicking
+function ScoreJustification({ buckets, keyCatalyst }: { buckets: any[]; keyCatalyst?: string }) {
+  return (
+    <div className="space-y-2 text-xs">
+      {keyCatalyst && (
+        <div className="flex gap-1.5 bg-yellow-400/5 border border-yellow-400/20 rounded px-2 py-1.5">
+          <span className="text-yellow-400 shrink-0">🔑</span>
+          <p className="text-yellow-200/80 leading-snug">{keyCatalyst}</p>
+        </div>
+      )}
+      {buckets.map((b: any) => {
+        const pct = b.max > 0 ? Math.round((b.score / b.max) * 100) : 0
+        const scoreColor = pct >= 70 ? 'text-emerald-400' : pct >= 45 ? 'text-yellow-400' : 'text-red-400'
+        return (
+          <div key={b.id} className="bg-dark-700/60 rounded p-2 space-y-1.5">
+            {/* Pillar header */}
+            <div className="flex items-center gap-1.5">
+              <span className="text-base leading-none">{BUCKET_ICONS[b.id] ?? '•'}</span>
+              <span className="text-slate-300 font-medium flex-1">{b.label}</span>
               <BucketBar score={b.score} max={b.max} />
-              <span className={clsx('font-mono w-9 text-right shrink-0', pct >= 75 ? 'text-emerald-400' : pct >= 50 ? 'text-yellow-400' : 'text-red-400')}>
+              <span className={clsx('font-mono text-right shrink-0 font-bold', scoreColor)}>
                 {b.score}/{b.max}
               </span>
-              {isOpen ? <ChevronUp className="w-2.5 h-2.5 text-slate-600 shrink-0" /> : <ChevronDown className="w-2.5 h-2.5 text-slate-600 shrink-0" />}
-            </button>
-            {isOpen && (
-              <div className="px-2 pb-2 border-t border-slate-700/30 space-y-2 pt-1.5">
-                {b.comment && (
-                  <p className="text-slate-500 italic">{b.comment}</p>
-                )}
-                {b.subs?.map((sub: any) => {
+            </div>
+            {/* Pillar comment */}
+            {b.comment && (
+              <p className="text-slate-400 leading-snug pl-1 border-l-2 border-slate-600">{b.comment}</p>
+            )}
+            {/* Sub-pillars */}
+            {b.subs?.length > 0 && (
+              <div className="pl-2 space-y-1.5 border-l border-slate-700/50 ml-1">
+                {b.subs.map((sub: any) => {
                   const subPct = sub.max > 0 ? Math.round((sub.score / sub.max) * 100) : 0
+                  const subColor = subPct >= 70 ? 'text-emerald-400' : subPct >= 45 ? 'text-yellow-400' : 'text-slate-500'
                   return (
-                    <div key={sub.id} className="pl-1 space-y-0.5">
-                      <div className="flex items-center gap-1.5">
-                        <span className="text-xs">{BUCKET_ICONS[sub.id] ?? '›'}</span>
+                    <div key={sub.id} className="space-y-0.5">
+                      <div className="flex items-center gap-1">
+                        <span className="text-[11px]">{BUCKET_ICONS[sub.id] ?? '›'}</span>
                         <span className="text-slate-500 flex-1 truncate">{sub.label}</span>
-                        <BucketBar score={sub.score} max={sub.max} />
-                        <span className={clsx('font-mono w-7 text-right shrink-0', subPct >= 75 ? 'text-emerald-400' : subPct >= 50 ? 'text-yellow-400' : 'text-slate-600')}>
+                        <span className={clsx('font-mono text-[10px] shrink-0', subColor)}>
                           {sub.score}/{sub.max}
                         </span>
                       </div>
                       {sub.comment && (
-                        <p className="text-slate-600 italic ml-4">{sub.comment}</p>
+                        <p className="text-slate-600 leading-snug text-[10px] pl-3">{sub.comment}</p>
                       )}
                     </div>
                   )
@@ -221,11 +249,16 @@ function TradeCard({ item, onAdd, macroInfo, addedInfo, profiles }: {
         )}
       </div>
 
-      {/* Score bar */}
+      {/* Score bar + 4-pillar mini breakdown */}
       {effectiveScore !== null && (
-        <div className="bg-dark-600 rounded-full h-1.5 mb-2">
-          <div className={clsx('h-1.5 rounded-full', scoreBg(effectiveScore))} style={{ width: `${effectiveScore}%` }} />
-        </div>
+        <>
+          <div className="bg-dark-600 rounded-full h-1.5 mb-1.5">
+            <div className={clsx('h-1.5 rounded-full', scoreBg(effectiveScore))} style={{ width: `${effectiveScore}%` }} />
+          </div>
+          {scoreInfo?.buckets?.length > 0 && (
+            <ScorePillars buckets={scoreInfo.buckets} />
+          )}
+        </>
       )}
 
       {/* EV / Profile match row — always shown when scored, helps understand why trade is/isn't logged */}
@@ -300,18 +333,21 @@ function TradeCard({ item, onAdd, macroInfo, addedInfo, profiles }: {
         </div>
       )}
 
-      {/* Expandable score breakdown */}
+      {/* Expandable score justification */}
       {effectiveScore !== null && (scoreInfo?.buckets?.length > 0 || Object.keys(breakdown).length > 0) && (
         <>
           <button onClick={() => setExpanded(!expanded)}
-            className="flex items-center gap-1 text-xs text-slate-600 hover:text-slate-400 mb-1.5">
+            className="flex items-center gap-1 text-xs text-slate-500 hover:text-slate-300 mb-1.5 transition-colors">
             {expanded ? <ChevronUp className="w-3 h-3" /> : <ChevronDown className="w-3 h-3" />}
-            Détail du score par pilier
+            {expanded ? 'Masquer la justification' : '↳ Justification du score'}
           </button>
           {expanded && (
             <div className="mb-2">
               {scoreInfo?.buckets?.length > 0 ? (
-                <BucketBreakdown buckets={scoreInfo.buckets} />
+                <ScoreJustification
+                  buckets={scoreInfo.buckets}
+                  keyCatalyst={scoreInfo.key_catalyst}
+                />
               ) : (
                 <div className="space-y-1 bg-dark-700/50 rounded p-2">
                   {Object.entries(breakdown).map(([k, v]: [string, any]) => (