feat: implémentation complète du système Célestopol 1922 pour FoundryVTT v13

- DataModels (character, npc, anomaly, aspect, attribute, equipment)
- ApplicationV2 sheets (character 5 tabs, npc 3 tabs, 4 item sheets)
- DialogV2 pour les jets de dés avec phase de lune
- Templates Handlebars complets (fiches PJ/PNJ, items, jet, chat)
- Styles LESS → CSS compilé (thème vert foncé / orange CopaseticNF)
- i18n fr.json complet (clés CELESTOPOL.*)
- Point d'entrée fvtt-celestopol.mjs avec hooks init/ready
- Assets : polices CopaseticNF, images UI, icônes items
- Mise à jour copilot-instructions.md avec l'architecture réelle

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

module/applications/sheets/npc-sheet.mjs

@@ -0,0 +1,57 @@
+import CelestopolActorSheet from "./base-actor-sheet.mjs"
+import { SYSTEM } from "../../config/system.mjs"
+
+export default class CelestopolNPCSheet extends CelestopolActorSheet {
+  /** @override */
+  static DEFAULT_OPTIONS = {
+    classes: ["npc"],
+    position: { width: 760, height: 600 },
+    window: { contentClasses: ["npc-content"] },
+  }
+
+  /** @override */
+  static PARTS = {
+    main:       { template: "systems/fvtt-celestopol/templates/npc-main.hbs" },
+    tabs:       { template: "templates/generic/tab-navigation.hbs" },
+    competences:{ template: "systems/fvtt-celestopol/templates/npc-competences.hbs" },
+    blessures:  { template: "systems/fvtt-celestopol/templates/npc-blessures.hbs" },
+  }
+
+  tabGroups = { sheet: "competences" }
+
+  #getTabs() {
+    const tabs = {
+      competences:{ id: "competences", group: "sheet", icon: "fa-solid fa-dice-d6", label: "CELESTOPOL.Tab.competences" },
+      blessures:  { id: "blessures",   group: "sheet", icon: "fa-solid fa-heart-crack", label: "CELESTOPOL.Tab.blessures" },
+    }
+    for (const v of Object.values(tabs)) {
+      v.active   = this.tabGroups[v.group] === v.id
+      v.cssClass = v.active ? "active" : ""
+    }
+    return tabs
+  }
+
+  /** @override */
+  async _prepareContext() {
+    const context  = await super._prepareContext()
+    context.tabs   = this.#getTabs()
+    context.stats  = SYSTEM.STATS
+    context.skills = SYSTEM.SKILLS
+    context.woundLevels = SYSTEM.WOUND_LEVELS
+    return context
+  }
+
+  /** @override */
+  async _preparePartContext(partId, context) {
+    context.systemFields = this.document.system.schema.fields
+    switch (partId) {
+      case "competences":
+        context.tab = context.tabs.competences
+        break
+      case "blessures":
+        context.tab = context.tabs.blessures
+        break
+    }
+    return context
+  }
+}