add trend UX + PHPStan level 6 clean (0 errors)

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

frontend/src/components/SpotPanel/SpotPanel.jsx

@@ -6,6 +6,12 @@ import './SpotPanel.css';
 const LEVEL_LABEL = { low: 'OK', medium: 'Risque', high: 'Impact' };
 const TYPE_ICON   = { beach: '🏖', port: '⚓', surf: '🏄', fishing: '🎣' };
 
+const TREND_CONFIG = {
+  increasing: { icon: '📈', label: 'Situation en dégradation', cls: 'trend--bad'  },
+  stable:     { icon: '➡️', label: 'Situation stable',         cls: 'trend--neutral' },
+  decreasing: { icon: '📉', label: 'Amélioration en cours',    cls: 'trend--good' },
+};
+
 const HORIZON_LABELS = { now: 'Maintenant', h6: '+6h', h12: '+12h', h24: '+24h', h48: '+48h' };
 
 export default function SpotPanel({ spot, activeStep, onClose }) {
@@ -82,13 +88,20 @@ export default function SpotPanel({ spot, activeStep, onClose }) {
                   </div>
                 </div>
 
+                {activeStep === 'now' && displayScore.trend && (() => {
+                  const t = TREND_CONFIG[displayScore.trend] ?? TREND_CONFIG.stable;
+                  return (
+                    <div className={`spot-panel__trend ${t.cls}`}>
+                      <span className="spot-panel__trend-icon">{t.icon}</span>
+                      <span className="spot-panel__trend-label">{t.label}</span>
+                    </div>
+                  );
+                })()}
+
                 <dl className="spot-panel__details">
                   {displayScore.distance != null && (
                     <><dt>Distance sargasses</dt><dd>{displayScore.distance} km</dd></>
                   )}
-                  {activeStep === 'now' && displayScore.trend && (
-                    <><dt>Tendance</dt><dd>{displayScore.trend}</dd></>
-                  )}
                   {activeStep === 'now' && displayScore.computedAt && (
                     <><dt>Calculé le</dt>
                     <dd>{new Date(displayScore.computedAt).toLocaleString('fr-FR')}</dd></>