Homogenize header: VIGUEUR threshold as subtitle like AME

Move vigueur value from standalone big number to inline subtitle (X)
in the card title, matching AME's (Seuil X) pattern.
Remove stat-big-value block from VIGUEUR card.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

templates/actor-sheet.hbs

@@ -73,11 +73,8 @@
 
       {{!-- VIGUEUR --}}
       <div class="stat-card card-vigueur">
-        <div class="stat-card-title">♥ Vigueur</div>
+        <div class="stat-card-title">♥ Vigueur <span class="stat-sub">({{system.sante.vigueur}})</span></div>
         <div class="stat-card-content">
-          <div class="stat-field stat-field-center">
-            <span class="stat-big-value">{{system.sante.vigueur}}</span>
-          </div>
           <div class="stat-field">
             <label>État</label>
             <select name="system.sante.etat">