How to distribute a Google Apps Script (processing Gmail mails) publicly?

Question

I developed a Google Apps Script to process some emails automatically (connected to Gmail), more or less like a bot, and it's working as expected. It runs every minute, using a Time-driven trigger Minutes timer > Every minute:

Is it possible to distribute this "script" for other users (including commercially), or will it necessarily be open-sourced? (note: Google Apps Scripts are using Javascript internally)

I see Deploy as web app, Deploy as API executable, Register in Chrome Web Store, Deploy as web add-on, Deploy from manifest, but I don't know which one to use to offer this service for other users.

Also, will it necessarily be on the Chrome Web Store or are there other ways to commercially distribute/grant access to a customer to such apps?

TL;DR: How to distribute to customers a Google Apps Script that processes Gmail emails? (that needs to run automatically every minute).

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Note: It seems that Gmail add-ons are available here: https://gsuite.google.com/marketplace/category/works-with-gmail. But it seems that we cannot sell an add-on commercially. Are Gmail add-ons necessarily free?

Note: the script is not linked to a precise browser or computer (thus it cannot be installed with a browser extension on a particular computer), it quietly runs on the Gmail server every minute.

Answer 1

Partial answer:

The page Restrictions about Gmail add-ons states that they don't provide a direct way to charge users to install an add-on:

We don't provide a way to charge users for installing add-ons, and add-ons can't include ads. However, you can roll your own payment system or call into an existing billing database. Your add-on can connect to non-Google services that bill users.

However, it's unclear for me if it's possible to run a time-driven background task (let's say once every 15 minutes) by a Gmail add-on. On the one hand, I see in the Restrictions page:

You can't create or use Apps Script simple or installable triggers in a Gmail add-on.

and time-driven triggers seem to be included in "simple" or "installable" category, but I'm not sure. For example, everyMinutes(n):

Specifies to run the trigger every n minutes. n must be 1, 5, 10, 15 or 30.

ScriptApp.newTrigger("myFunction")
    .timeBased()
    .everyMinutes(10)
    .create();

On the other hand, I see an example here with so-called Universal Actions:

/**
 * Run background tasks, none of which should alter the UI.
 * Also records the time of sync in the script properties.
 *
 * @param {Object} e an event object
 */
function runBackgroundSync(e) {
    ...