feat: Loksyu & TinJi standalone AppV2 apps with chat buttons and dice automation

- CDELoksyuApp: standalone HandlebarsApplicationMixin(ApplicationV2) app
  - 5-element Wu Xing grid with yin/yang inputs per element
  - Per-element reset buttons + global reset-all
  - Auto-refresh via updateActor hook

- CDETinjiApp: standalone AppV2 for the collective Tin Ji dice pool
  - Large neon counter with +/- buttons and direct input
  - Spend button sends a chat message with remaining count

- singletons.js: shared utilities
  - getSingletonActor: find or auto-create singleton actor
  - updateLoksyuFromRoll: compute lokAspect from Wu Xing cycle, update yin/yang
  - updateTinjiFromRoll: add tinji face count to value

- rolling.js: auto-update both singletons after every dice roll
  (weapon path + main roll path)

- system.js: renderChatLog hook injects Loksyu/TinJi footer buttons
  in the chat sidebar

- loksyu.js / tinji.js: actor sheets redirect to standalone apps
  when opened via the sidebar

- CSS: .cde-loksyu-standalone, .cde-tinji-standalone, .cde-chat-app-buttons,
  .cde-tinji-spend-msg styles added

- i18n: new keys in fr-cde.json and en-cde.json for all new UI strings
  (LoksyuNotFound, TinjiNotFound, Reset, ResetAll, SpendTinji, etc.)

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

src/ui/apps/loksyu-app.js

@@ -0,0 +1,121 @@
+import { getSingletonActor } from "./singletons.js"
+import { ACTOR_TYPES } from "../../config/constants.js"
+
+const SYSTEM_ID = "fvtt-chroniques-de-l-etrange"
+
+export class CDELoksyuApp extends foundry.applications.api.HandlebarsApplicationMixin(
+  foundry.applications.api.ApplicationV2
+) {
+  static DEFAULT_OPTIONS = {
+    id: "cde-loksyu-app",
+    tag: "div",
+    window: {
+      title: "CDE.Loksyu",
+      icon: "fas fa-yin-yang",
+      resizable: false,
+    },
+    classes: ["cde-app", "cde-loksyu-standalone"],
+    position: { width: 540, height: "auto" },
+    actions: {
+      resetElement: CDELoksyuApp.#onResetElement,
+      resetAll:     CDELoksyuApp.#onResetAll,
+    },
+  }
+
+  static PARTS = {
+    main: {
+      template: `systems/${SYSTEM_ID}/templates/apps/cde-loksyu-app.html`,
+    },
+  }
+
+  /** @type {Actor|null} */
+  #actor = null
+  /** @type {Function|null} bound hook handler */
+  #updateHook = null
+
+  /** Singleton accessor — open or bring to front */
+  static open() {
+    const existing = Object.values(foundry.applications.instances ?? {}).find(
+      (app) => app instanceof CDELoksyuApp
+    )
+    if (existing) { existing.bringToFront(); return existing }
+    const app = new CDELoksyuApp()
+    app.render(true)
+    return app
+  }
+
+  async _prepareContext() {
+    this.#actor = await getSingletonActor(ACTOR_TYPES.loksyu)
+    if (!this.#actor) return { hasActor: false }
+
+    const sys = this.#actor.system
+    const ELEMENTS = [
+      { key: "wood",  nameKey: "CDE.Wood",  qualKey: "CDE.WoodQualities",  img: `systems/${SYSTEM_ID}/images/cde_bois.webp` },
+      { key: "fire",  nameKey: "CDE.Fire",  qualKey: "CDE.FireQualities",  img: `systems/${SYSTEM_ID}/images/cde_feu.webp` },
+      { key: "earth", nameKey: "CDE.Earth", qualKey: "CDE.EarthQualities", img: `systems/${SYSTEM_ID}/images/cde_terre.webp` },
+      { key: "metal", nameKey: "CDE.Metal", qualKey: "CDE.MetalQualities", img: `systems/${SYSTEM_ID}/images/cde_metal.webp` },
+      { key: "water", nameKey: "CDE.Water", qualKey: "CDE.WaterQualities", img: `systems/${SYSTEM_ID}/images/cde_eau.webp` },
+    ]
+
+    return {
+      hasActor: true,
+      canEdit:  this.#actor.isOwner,
+      elements: ELEMENTS.map((el) => ({
+        ...el,
+        yang: sys[el.key]?.yang?.value ?? 0,
+        yin:  sys[el.key]?.yin?.value  ?? 0,
+      })),
+    }
+  }
+
+  _onRender(context, options) {
+    super._onRender(context, options)
+    this.#bindInputs()
+
+    // Subscribe to actor updates to keep the app live
+    this.#updateHook = Hooks.on("updateActor", (actor) => {
+      if (actor.id === this.#actor?.id) this.render()
+    })
+  }
+
+  _onClose(options) {
+    if (this.#updateHook !== null) {
+      Hooks.off("updateActor", this.#updateHook)
+      this.#updateHook = null
+    }
+    super._onClose(options)
+  }
+
+  #bindInputs() {
+    const inputs = this.element?.querySelectorAll("input[data-field]")
+    if (!inputs?.length) return
+    inputs.forEach((input) => {
+      input.addEventListener("change", async (ev) => {
+        const field = ev.currentTarget.dataset.field
+        const val   = parseInt(ev.currentTarget.value, 10)
+        if (!field || isNaN(val)) return
+        await this.#actor?.update({ [field]: Math.max(0, val) })
+      })
+    })
+  }
+
+  static async #onResetElement(event, target) {
+    const key = target.dataset.element
+    if (!key || !this.#actor) return
+    await this.#actor.update({
+      [`system.${key}.yin.value`]:  0,
+      [`system.${key}.yang.value`]: 0,
+    })
+  }
+
+  static async #onResetAll(_event, _target) {
+    if (!this.#actor) return
+    const KEYS = ["wood", "fire", "earth", "metal", "water"]
+    const update = {}
+    for (const k of KEYS) {
+      update[`system.${k}.yin.value`]  = 0
+      update[`system.${k}.yang.value`] = 0
+    }
+    await this.#actor.update(update)
+  }
+}