Steps to reproduce
1. Set the company's partner timezone to a negative UTC offset (e.g. America/Argentina/Buenos_Aires, UTC-3).
2. Create a sale order for a storable subscription product and confirm it.
3. Open the generated delivery order and check its Scheduled Date.

Issue
The scheduled date on the first delivery renders as the previous day. `_prepare_procurement_values` writes `date_planned` as `current_period_start`, which is a plain `fields.Date` value
(https://github.com/odoo/enterprise/blob/ba41d7de3c0474286e3e9319710fdacfb95d3e2c/sale_subscription_stock/models/sale_order_line.py#L156). When a `date` is stored in the `Datetime` column `stock.move.date`, Odoo anchors it at midnight UTC; in any negative-offset timezone this renders as the previous day (e.g. `2022-03-02 00:00 UTC` shows as `2022-03-01 21:00` in UTC-3). The non-subscription path does not hit this because it resolves `date_planned` through `_expected_date()`, which returns `order_id.date_order` — a full `Datetime` set to `fields.Datetime.now()` at confirmation (https://github.com/odoo/odoo/blob/996702b0d5c518db2ac6f0b144e7835b27c29736/addons/sale/models/sale_order_line.py#L1398).

The same midnight-UTC drift also affects later recurrences, where `current_period_start` falls back to `last_invoice_date` — another `Date`.

Solution
Split the two cases explicitly:
- First delivery (`last_invoice_date` unset): set `date_planned` to `order_id.date_order`, matching the non-subscription flow.
- Subsequent deliveries: localize `last_invoice_date` at `00:00` in the company timezone before converting back to UTC, reusing the pattern already applied to reordering rules (https://github.com/odoo/odoo/blob/20a0eee2d03293564320c268252a0353781d99ea/addons/stock/models/stock_orderpoint.py#L722).

opw-6133831

Forward-Port-Of: odoo/enterprise#116593
Forward-Port-Of: odoo/enterprise#115100

### Steps to Reproduce:
- Enable dropshipping in Inventory settings
- Create a product with inventory tracking enabled
- Enable dropship under the Inventory tab for the product
- Add a vendor and quantity under the Purchase tab
- Create a sale order for the product
- Go to the Purchase stat button and confirm the order
- Click on the Dropship stat button and validate the transfer
- Open Helpdesk and create a new ticket for the same partner

### Issue:
The "Returns" stat button is not visible for dropshipped deliveries.

### Current behaviour:
- The helpdesk ticket allows returns of customer orders only if the order is outgoing. However, this does not cover the usecase where the order was dropshipped and still needs to be returned to the vendor.
- With the current behavior, the user needs to find the customer's order to return the transfer as it is not possible to do from the ticket.

### Expected behaviour:
Helpdesk tickets should also allow returns of dropshipped transfers (done and linked to the SO).

### Fix:
The helpdesk return logic was limited to only 'outgoing' pickings. This commit extends the 'return' button should be visible if there is at least one delivery or dropship order linked to the partner of the ticket

Issue:https://github.com/odoo/enterprise/pull/81378

task-4881338

Forward-Port-Of: odoo/enterprise#91402

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## Short functional explanation of the error
When an employee has multiple overtimes for the same day, including one that doesn't have a check-out date. When running the scheduled action `Attendance: Automatically check-out employees`, an error occurs: `odoo.exceptions.ValidationError: Duration must be positive and cannot exceed 24 hours.`

## Reproduction Steps
1. Create an employee. Set their timezone to UTC and the Overtime Ruleset to Default Ruleset in the settings tab.
In the Payroll tab, set a contract start date.
2. Set their Working Hours to a fixed 40 hours/week. Set the timezone of the Working Schedule to UTC.
3. Go to attendances and create 2 attendances on a Sunday: one from 06:00 to 06:01 and a second that starts at 06:02 but that doesn't have a checkout date.
4. Go to Settings and enable Automatic Checkout. Leave the Tolerance to 2 hours.
5. Enable debug mode and go to Scheduled Actions. Look for `Attendance: Automatically check-out employees` and run it manually.

### Expected behavior
As the tolerance is 2 hours, the second attendance check-out time should be set at 08:01.

### Unexpected behavior
An error occurs:
`odoo.exceptions.ValidationError: Duration must be positive and cannot exceed 24 hours.`

## Origin of the issue
We retrieve overtime intervals with the domain:
https://github.com/odoo/enterprise/blob/64f813dab727d76286c1ff6c80c08cb6a6737b49/hr_work_entry_attendance/models/hr_version.py#L34-L42 This will make us retrieve all the overtimes for a given day, even if overtimes belong to different attendances.

However, this means that we will retrieve several times the same overtimes, as this piece of code is executed in this context:

https://github.com/odoo/enterprise/blob/64f813dab727d76286c1ff6c80c08cb6a6737b49/hr_work_entry_attendance/models/hr_attendance.py#L35 https://github.com/odoo/enterprise/blob/64f813dab727d76286c1ff6c80c08cb6a6737b49/hr_work_entry_attendance/models/hr_attendance.py#L43

This results in the generation of intervals containing multiple times the same overtimes. We then sum their duration to later create work entries:
https://github.com/odoo/enterprise/blob/64f813dab727d76286c1ff6c80c08cb6a6737b49/hr_work_entry_attendance/models/hr_attendance.py#L47 As we try to create a work entry with too much overtime, that exceeds 24 hours, it raises a validation error.
Moreover, as the overtime hours are always stored in UTC, it makes sense to always keep the timezone as UTC when performing a `_read_group` .
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opw-6036064

Forward-Port-Of: odoo/enterprise#116194