Current behaviour:
Users are unable to select certain Starshipit delivery services. Delivery methods are configured in Odoo before address or package data is available. Since Starshipit requires this data to determine availability, it returns an incomplete list during setup.

Expected behaviour:
Users should be able to view and select from the complete list of valid delivery services based on the actual Sales Order details (address, weight, and volume).

Steps to reproduce:
1. Create new delivery method
2. Configure Starshipit API credentials.
3. Attempt to select a service.
4. Observe that not all service is shown from the available options.

Cause of the issue:
Starshipit filters services based on sender, receiver, and package info. Odoo requests the service list during initial configuration without this context, resulting in an incomplete list of methods.

Fix:
Introduce a mechanism in the Sales Order flow to add delivery methods. Send the complete shipment details (addresses, weight) to Starshipit to retrieve the accurate list of services and allow the user to select them.

Forward-Port-Of: odoo/enterprise#103316

Link to Avalara (Avatax) documentation:
https://developer.avalara.com/api-reference/avatax/rest/v2/models/LineItemModel/

Expected Behaviour:
The itemCode sent to the AvaTax API should be 50 characters or fewer
to comply with Avalara's field length constraints.

Actual Behaviour before the Fix:
When an itemCode exceeded 50 characters, the system attempted to send
the request as-is. This resulted in the AvaTax API returning an error,
causing the transaction or tax calculation to fail.

Behaviour with the Fix:
The system now ensures that the itemCode adheres to the 50-character
limit before the API call is made, by trancating the code to the
first 50 characters if it exceeds 50 characters. This prevents API
rejection and ensures successful tax processing for items with
long identifiers.

Steps to reproduce:
1. Create or select a product/item with a reference (or barcode if
   using UPC) longer than 50 characters.
2. Trigger an action that calculates tax via the AvaTax
   integration (e.g., creating an invoice or updating a line item).
3. Observe the API response.

- Before fix: API returns a validation error regarding the
  itemCode length.
- After fix: Request is successful as the itemCode is
  properly handled/validated.

opw-5406451

Forward-Port-Of: odoo/enterprise#105017

_
## Short functional explanation of the error
Let's say a customer has made 2 sales order of 2 different serives: one service is prepaid, the other one is billed based on timesheets. When we create a ticket related to this customer in the helpdesk app, the ticket automatically fills the Sales Order Item field with the prepaid service. If we remove this Sales Order Item, create a timesheet in which we set the Sales Order Item to be the timesheeted service, and press save, the Sales Order Item of the timesheet will disappear.

## Reproduction Steps
1. Create 2 products: one service based on timesheets and one service prepaid. Make sure that they create an empty project on order.
2. Create 2 quotations for the same partner: one that contains the first product you created and a second one containing the second product. Click on confirm.
3. Go to Helpdesk > Configuration > Helpdesk teams. Click on one team and under Track and Bill time, enable both Timesheets and Time Billing.
4. Create a Helpdesk ticket for the team you setup. Under customer, enter the name of the partner in the quotations.
5. Click on the ticket. The quotation related to the prepaid service should appear as the field Sales Order item on the ticket. Remove it, click on the Timesheet tab, and add a line in which, for the Sales Order Item field of the timesheet, you'd enter the quotation for the timesheeted service.
6. Hit save.

## Expected behavior
The quotation entered as Sales Order Item field in the timesheet persists, while the Sales Order Item field of the ticket stays empty.

## Unexpected Behavior
the Sales Order Item field in the timesheet tab disappears.

## Origin of the issue
The field is_so_line_edited was kept at false as the widget used to
update its value wasn't used in the view.

_
opw-5384256

Forward-Port-Of: odoo/enterprise#102345