Export of clients from a custom PHP script + DB (script refinement)

Good afternoon, it is required to refine the script that collects information about clients in its own database.

The logic of the script is as follows: after registering a discount card, an email is sent containing a PDF with information about the client, the script retrieves it from the email and enters all client data into the database, marking the email as read. If something goes wrong, it logs that it failed.

The interface of the script is minimalist and simply performs its function - https://s.obio.me/2002695116_S967.jpg.

Now there is a need not only to accumulate clients but also to export client information in the required format for subsequent export to the email marketing script. 

1. It is necessary to create a button in the admin panel, which can be named - mass selection, when clicked, a window should open for inserting numbers in the following format - https://s.obio.me/70022373_S859.jpg. The form should automatically clear these points and leave only numerical values or simply recognize only numerical values. Each number should always be on a new line or separated by a comma. 
2. Also, make it possible to search by email addresses in bulk, like email addresses each on a new line or separated by a comma.
3. When clicking the button - filter (the name is not critical): a list of people should be generated - https://s.obio.me/996068012_S964.jpg, for whom matches were found. 
4. At the bottom of this list or somewhere on the panel, add a button - Copy and export. When clicking the button, the entire list is copied to the clipboard in the format: Each client on a new line, client data ID phone, address, and others, separated by commas. If exporting, clicking will download a CSV file with all data split into columns or separated by commas. 
5. Add to the rights section - https://s.obio.me/1156208973_S965.jpg who can perform mass selection and who cannot.  Consider a checkbox - only for their own - for example, if it is checked, mass selection will only work for their own, for those in which this person is listed as a sponsor - https://s.obio.me/1577852613_S966.jpg  

P.S. Consider that the script adapts to mobile devices and ensure that the new buttons and interface parts will look correct in the mobile version.

Minor edits:

• It is necessary to add the ability to edit the client Number (id) directly + the ability to delete, currently to edit you need to add it again, but at the same time, there is no option to delete the old one, it needs to be added so that it can be deleted if necessary.