test: Add playwright main usage test

electron/ipc/system.ts

@@ -535,4 +535,26 @@ export function setupSystemHandlers(): void {
       request.end();
     });
   });
+
+  ipcMain.handle('context-menu-command', (_event, command: string) => {
+    const allowedCommands = ['cut', 'copy', 'paste', 'selectAll'] as const;
+
+    if (!allowedCommands.includes(command as typeof allowedCommands[number])) {
+      return;
+    }
+
+    const mainWindow = getMainWindow();
+    const webContents = mainWindow?.webContents;
+
+    if (!webContents) {
+      return;
+    }
+
+    switch (command) {
+      case 'cut': webContents.cut(); break;
+      case 'copy': webContents.copy(); break;
+      case 'paste': webContents.paste(); break;
+      case 'selectAll': webContents.selectAll(); break;
+    }
+  });
 }