Add initial Pico-8 cartridges for testing

- Created test_cart.p8 with basic drawing functionality and a print statement.
- Created test_unix.p8 with a simple initialization function.

preload.js

@@ -59,6 +59,122 @@ const api = {
 
     return ipcRenderer.invoke("player:writeCart", cartContent);
   },
+
+  /**
+   * Minimizes the current window.
+   *
+   * @returns {Promise<void>}
+   */
+  minimizeWindow() {
+    return ipcRenderer.invoke("window:minimize");
+  },
+
+  /**
+   * Toggles the current window maximize state.
+   *
+   * @returns {Promise<boolean>}
+   */
+  toggleMaximizeWindow() {
+    return ipcRenderer.invoke("window:toggle-maximize");
+  },
+
+  /**
+   * Closes the current window.
+   *
+   * @returns {Promise<void>}
+   */
+  closeWindow() {
+    return ipcRenderer.invoke("window:close");
+  },
+
+  /**
+   * Reads the current maximize state for the window.
+   *
+   * @returns {Promise<boolean>}
+   */
+  getWindowMaximized() {
+    return ipcRenderer.invoke("window:is-maximized");
+  },
+
+  /**
+   * Subscribes to maximize state changes.
+   *
+   * @param {(isMaximized: boolean) => void} callback
+   * @returns {() => void}
+   */
+  onWindowMaximizedChanged(callback) {
+    if (typeof callback !== "function") {
+      return () => {};
+    }
+
+    const listener = (_event, isMaximized) => {
+      callback(Boolean(isMaximized));
+    };
+    ipcRenderer.on("window:maximized-changed", listener);
+    return () => {
+      ipcRenderer.removeListener("window:maximized-changed", listener);
+    };
+  },
+
+  /**
+   * Saves a tileset image file to the application data directory.
+   *
+   * @param {Uint8Array} fileBuffer The PNG file data
+   * @param {string} suggestedName Suggested filename
+   * @returns {Promise<{ filePath: string, fileName: string }>}
+   */
+  saveTileset(fileBuffer, suggestedName) {
+    if (!(fileBuffer instanceof Uint8Array)) {
+      return Promise.reject(new TypeError("File buffer must be a Uint8Array"));
+    }
+    if (typeof suggestedName !== "string") {
+      return Promise.reject(new TypeError("Suggested name must be a string"));
+    }
+
+    return ipcRenderer.invoke("tileset:save", fileBuffer, suggestedName);
+  },
+
+  /**
+   * Shows a tileset file in the system file explorer.
+   *
+   * @param {string} filePath Path to the tileset file
+   * @returns {Promise<void>}
+   */
+  showTilesetInFolder(filePath) {
+    if (typeof filePath !== "string") {
+      return Promise.reject(new TypeError("File path must be a string"));
+    }
+
+    return ipcRenderer.invoke("tileset:show-in-folder", filePath);
+  },
+
+  /**
+   * Reloads a tileset image from disk.
+   *
+   * @param {string} filePath Path to the tileset file
+   * @returns {Promise<{ buffer: number[] }>}
+   */
+  reloadTileset(filePath) {
+    if (typeof filePath !== "string") {
+      return Promise.reject(new TypeError("File path must be a string"));
+    }
+
+    return ipcRenderer.invoke("tileset:reload", filePath);
+  },
+
+  /**
+   * Gets PICO-8 cart statistics using p8tool stats command.
+   *
+   * @param {string} cartContent Complete .p8 cart file content
+   * @returns {Promise<{ tokens: number, lines: number, chars: number, rawOutput: string }>}
+   */
+  getCartStats(cartContent) {
+    if (typeof cartContent !== "string") {
+      return Promise.reject(new TypeError("Cart content must be a string"));
+    }
+
+    return ipcRenderer.invoke("cart:get-stats", cartContent);
+  },
 };
 
 contextBridge.exposeInMainWorld("electronAPI", api);