Prerequisites:
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1. Set up incoming mail server with Create a New Record set to Helpdesk Ticket
2. From Settings, create one Alias Domain

Steps to reproduce:
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1. Install Helpdesk module
2. Open Helpdesk Team > Settings
3. Inside Channels, Set the mail used for the incoming server and the alias created
4. Set Accept Emails From to Everyone
5. Create a new contact with multiple emails (eg: `a@b.com`, `c@d.com`)
6. From Fiest mail (eg: `a@b.com`), Send one mail to mail set in the helpdesk team alias mail.
7. Open Incoming mail sever  > Click on Fetch Now
8. Open Created Contact

Observation:
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The contact's email field is overwritten. The second email address (e.g. `c@d.com`) is lost

Issue:
------------------------------
After `create`, since `partner_email` was stored with a value that differs from `partner_id.email`, the inverse method `_inverse_partner_email` kicks in. This is where `_get_partner_email_update()` is called. In `_get_partner_email_update()` `tools.email_normalize()` only handles a single email. When the partner has multiple email, the normalization keeps both, while the ticket email normalizes to just have one mail. The strict `!=` comparison fails, triggering the unwanted update.

https://github.com/odoo/enterprise/blob/7c23efafe368787c858db31cec075f642ae6715b/helpdesk/models/helpdesk_ticket.py#L363-L369

Solution:
------------------------------
Instead of comparing the full normalized strings, we should check whether the ticket's normalized email is contained within the set of the partner's normalized emails

Note for reviewer
-----------------------------
After discussion with the PO (LNA), his opinion is that having multiple email addresses in a single field is not a good practice. This use case is only semi-supported in Odoo, it may work in some cases, but it is not reliable. The recommended approach is to create separate contacts for each email address.

That said, we should also avoid automatically clearing or altering the existing value in the field.

Based on this, I have implemented a minimal fix that prevents altering the existing value in the field. I am leaving it up to the review to decide whether this fix is worth keeping from a technical standpoint.


opw-5478067

Forward-Port-Of: odoo/enterprise#107808

When the user sends a push notification through Social Marketing, the application displays two notification popups because:

1. The Firebase SDK automatically displays a notification popup if the request made to Firebase includes a `notification` field.
2. Our service worker displays a notification popup when receiving a background message from Firebase.

To prevent duplicate notifications, we will remove the custom event listeners in the service worker and update the request made to Firebase so that the Firebase SDK opens a notification for us.

Furthermore, this PR fixes the error `Failed to execute 'subscribe' on 'PushManager': Subscription failed - no active Service Worker` occurring when the user accepts the push notifications.

To fix that issue, we will:
1. Ensure that the service worker reaches the `ready` state before communicating with it.
2. Set the service worker's scope to `/` so it controls all pages on the origin, ensuring push subscriptions succeed and the worker can communicate with any page.

Finally, we will use the legacy `importScripts` syntax to load Firebase dependencies because the ECMAScript module syntax is not supported for service workers in Firefox. This approach improves push notification compatibility across browsers.

Task-5124645

Forward-Port-Of: odoo/enterprise#96029