feat: Implement a movable and detachable Daggerheart countdown tracker with UI and module integration.

scripts/module.js

@@ -0,0 +1,101 @@
+import { createMovableCountdownsClass } from './MovableCountdowns.js';
+
+const MODULE_ID = 'dh-countdownsplus';
+let MovableCountdowns;
+
+Hooks.once('init', () => {
+    console.log(`${MODULE_ID} | Initializing Daggerheart Countdowns Plus`);
+
+    // Register settings or other init logic if needed
+});
+
+Hooks.on('ready', () => {
+    // Ensure the system's countdown class exists
+    if (!CONFIG.ui.countdowns) {
+        console.error(`${MODULE_ID} | CONFIG.ui.countdowns not found. Is Daggerheart system initialized?`);
+        return;
+    }
+
+    // Create our class extending the system's class
+    MovableCountdowns = createMovableCountdownsClass(CONFIG.ui.countdowns);
+
+    // Initial check to see if we should inject button
+    hookSystemCountdowns();
+});
+
+function hookSystemCountdowns() {
+    // We want to hook into the render of the system's countdown app.
+    // The system app is likely a singleton at ui.countdowns.
+
+    // Hook on renderDhCountdowns (name of the class in system is DhCountdowns)
+    Hooks.on('renderDhCountdowns', (app, html, data) => {
+        // Only inject if this is the SYSTEM one, not our movable one (ours inherits, so it might trigger this hook too?)
+        // DhCountdowns extends ApplicationV2. AppV2 emits 'renderApplicationV2' and 'renderMyClass'.
+        // So 'renderDhCountdowns' will fire for both.
+
+        if (app instanceof MovableCountdowns) return;
+
+        // Find the header to inject button
+        // html is the HTMLElement in AppV2 hooks
+        const header = html.querySelector('.window-header');
+        if (!header) return;
+
+        // Check if button already exists
+        if (header.querySelector('[data-action="detach-countdowns"]')) return;
+
+        // Create Detach Button
+        const detachTooltip = "Detach"; // TODO: Localize
+        const detachBtn = document.createElement('a'); // System uses <a> for header controls
+        detachBtn.className = 'header-control';
+        detachBtn.dataset.tooltip = detachTooltip;
+        detachBtn.dataset.action = 'detach-countdowns';
+        detachBtn.innerHTML = '<i class="fa-solid fa-up-right-from-square"></i>';
+
+        // Add listener
+        detachBtn.addEventListener('click', async (ev) => {
+            ev.preventDefault();
+            ev.stopPropagation();
+
+            // Open Movable
+            // We assume singleton pattern for movable too
+            let movable = Object.values(ui.windows).find(w => w instanceof MovableCountdowns);
+            if (!movable) {
+                movable = new MovableCountdowns();
+            }
+            await movable.render({ force: true });
+
+            // Close/Hide System App
+            // Suppress future renders
+            if (app) {
+                app._suppressed = true;
+                await app.close();
+            }
+        });
+
+        // Insert before the "Close" button? System one doesn't have close button.
+        // Insert at end or specific position?
+        // System header controls: Edit, Toggle Mode.
+        // Let's prepend or append.
+        header.insertAdjacentElement('beforeend', detachBtn);
+    });
+
+    // Patch system render to respect suppression
+    if (ui.countdowns && !ui.countdowns._patched) {
+        const originalRender = ui.countdowns.render.bind(ui.countdowns);
+        ui.countdowns.render = function (options, ...args) {
+            if (this._suppressed) {
+                // Update internal state but don't show
+                // If data update, we might need to update OUR instance?
+                // But socket hooks call render() on ui.countdowns.
+                // We should notify Movable if it's open.
+
+                const movable = Object.values(ui.windows).find(w => w instanceof MovableCountdowns);
+                if (movable) movable.render();
+
+                return this;
+            }
+            return originalRender(options, ...args);
+        };
+        ui.countdowns._patched = true;
+    }
+}