Fix creature sheet: complete TECHNIQUE tab + copper theme

- Fix tabGroups 'stats'→'principal' (tab content was invisible)
- Add 'creature' CSS class to distinguish from personnage sheet
- New header layout: stat cards (Ressources, Vigueur, Combat)
- Rewrite creature template with full TECHNIQUE tab content:
  * Attributes with icons and level dropdowns (0-35)
  * Vitesse input
  * Santé section (Vigueur seuil)
  * Actions de combat (Initiative, Monté/Déf. totale, Assommer,
    Coup bas, Immobiliser, Repousser, Désengager)
  * Adversités section (reuses personnage CSS classes)
- Copper/orange CSS theme for .creature class overrides
- Add .stat-derived-value CSS for non-editable derived stats

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

modules/applications/sheets/mournblade-cyd2-creature-sheet.mjs

@@ -6,7 +6,7 @@ export default class MournbladeCYD2CreatureSheet extends MournbladeCYD2ActorShee
   /** @override */
   static DEFAULT_OPTIONS = {
     ...super.DEFAULT_OPTIONS,
-    classes: [...super.DEFAULT_OPTIONS.classes],
+    classes: [...super.DEFAULT_OPTIONS.classes, "creature"],
     window: {
       ...super.DEFAULT_OPTIONS.window,
       title: "SHEETS.Actor.creature",
@@ -21,7 +21,7 @@ export default class MournbladeCYD2CreatureSheet extends MournbladeCYD2ActorShee
   };
 
   /** @override */
-  tabGroups = { primary: "stats" };
+  tabGroups = { primary: "principal" };
 
   /** @override */
   async _prepareContext() {
@@ -39,6 +39,7 @@ export default class MournbladeCYD2CreatureSheet extends MournbladeCYD2ActorShee
     context.talents = foundry.utils.duplicate(actor.getTalents?.() ?? []);
     context.protectionTotal = actor.getProtectionTotal?.() ?? 0;
     context.adversiteTotal = (actor.system.adversite?.bleue || 0) + (actor.system.adversite?.rouge || 0) + (actor.system.adversite?.noire || 0);
+    context.initiative = context.combat?.initTotal ?? 0;
     return context;
   }
 }