ux: refonte jauge — label dominant, score /100 en détail discret

- "Indice de risque" en petit header explicite au-dessus
- Le label (VEILLE / RISQUE / IMPACT) devient l'élément visuel principal (30px)
- Le nombre /100 rétrogradé en hint discret sous la barre
- Suppression de l'ambiguïté "est-ce une note ou un risque ?"

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

frontend/src/components/SpotPanel/SpotPanel.jsx

@@ -110,19 +110,15 @@ export default function SpotPanel({ spot, activeStep, onClose }) {
                 })()}
 
                 <div className={`spot-panel__gauge gauge--${lvl}`}>
-                  <div className="spot-panel__gauge-top">
-                    <span className="spot-panel__gauge-label">{scoreLabel(displayScore.value, lvl)}</span>
-                    <span className="spot-panel__gauge-score">
-                      {displayScore.value}
-                      <span className="spot-panel__gauge-max">/100</span>
-                    </span>
-                  </div>
+                  <p className="spot-panel__gauge-header">Indice de risque</p>
+                  <span className="spot-panel__gauge-label">{scoreLabel(displayScore.value, lvl)}</span>
                   <div className="spot-panel__gauge-track">
                     <div
                       className="spot-panel__gauge-fill"
                       style={{ width: `${displayScore.value}%` }}
                     />
                   </div>
+                  <p className="spot-panel__gauge-hint">{displayScore.value} / 100</p>
                 </div>
 
                 {activeStep === 'now' && displayScore.trend && (() => {