Steps to reproduce:
---------------------------------------
1. Install Subscription Module
2. Create and Confirm SO with no recurring plan and a non-recurring product
3. Add a recurring product > Save SO > Observe the User Error
4. Now add the same recurring product through Catalog View

Observation:
---------------------------------------
No User Error raised stating
'You cannot save a sale order with recurring product and no subscription plan.'

Issue:
---------------------------------------
When you manually add a line and click 'Save', the constraint (`_constraint_subscription_plan`) is triggered and raised `UserError` https://github.com/odoo/enterprise/blob/434d88960abb5e424fdc1106fc93935d328bff78/sale_subscription/models/sale_order.py#L176-L177

When you add a product via the catalog view, it calls `_update_order_line_info` which directly creates/updates order lines, Which do not trigger the python constraint.
https://github.com/odoo/odoo/blob/ef9772bba1515bdaf5410c3af5a3e395f562d513/addons/sale/models/sale_order.py#L1926-L1933

Solution:
---------------------------------------
Two private helpers are introduced:
* `_is_exempt_from_subscription_plan_check`: single source of truth for all exempt states (draft, cancelled, upsell, and legacy upgrade orders).
* `_check_recurring_plan_mismatch`: raises a `UserError` when the order has or will have a recurring product but no subscription plan, reusing the exemption helper so both call sites stay in sync.

`_constraint_subscription_plan` is refactored to delegate to these helpers, and `_update_order_line_info` is overridden to call `_check_recurring_plan_mismatch` before the catalog update is applied, ensuring consistent validation across both entry points.

opw-6194865

Forward-Port-Of: odoo/enterprise#122799
Forward-Port-Of: odoo/enterprise#117879

Steps to Reproduce
---
- Create two different working schedules with different public holidays
- Assign employees to specific working schedules
- Set company default working schedule to a different schedule
- Login as employee with specific working schedule
- Navigate to Timesheets app -> My Timesheets
- Observe public holidays and personal time-off displayed in the timesheet grid

Issue
---
- The timesheet grid displays unavailable dates (public holidays, weekends) from the company's default working schedule instead of the employee's assigned working schedule.
- Personal time-off requests are not reflected as unavailable dates in the timesheet grid.

Current Behaviour
---
- Public holidays shown are always from the company's default working schedule, ignoring employee-specific working schedule assignments.
- Employee's approved time-off requests don't appear as unavailable in the timesheet.

Expected Behaviour
---
- Public holidays should display based on the employee's assigned working schedule, with company schedule as fallback only when no specific schedule is assigned.
- Employee's personal time-off requests should appear as unavailable dates.
- This should align with Time Off app behavior.

Fix
---
- Included employee-specific work interval calculation with personal time-off requests.
- Added support for contract-based calendar changes and calendar validity periods.
- Implemented proper fallback when valid intervals are not found.

task-4997080

Forward-Port-Of: odoo/enterprise#95458

The `body` field on `whatsapp.message` was defined with `related_sudo=False` with the intent of restricting access to messages from restricted records. However, this was never actually providing any security value because [`mail.message.fetch()`] was overriding it with `self.sudo()` till `v19.1`, meaning the body was always fetched as superuser regardless:
```py
    web_search_read() -> search_fetch()
    -> fields.py _compute_related()
    -> record[self.related_field.name]  # triggers fetch of mail.message.body
    -> models.py _fetch_field()
    -> mail_message.py fetch()
    -> self = self.sudo()  # sudo hack overrides related_sudo=False silently
```
In `v19.2`, the `fetch()` sudo hack was intentionally removed (see commit odoo/odoo@4727f12d274a0b2d7c455363d189565bd8fb2e7a) as access rights are now cached and can be checked without a performance penalty. This exposed the broken `related_sudo=False` which now causes an `AccessError` when trying to read the body of a `whatsapp.message` whose linked `mail.message` points to a document the current user cannot access (e.g. `purchase.order`).

Access control on `whatsapp.message` is already correctly enforced at the `ir.rule` level:
- Regular users can only see messages they created (`create_uid = user.id`)
- WA Admins can see all messages

We have upgrade requests failing on this issue: TBG-[2765]

[`mail.message.fetch()`]: https://github.com/odoo/odoo/blob/saas-19.1/addons/mail/models/mail_message.py#L812-L819
[2765]: https://upgrade.odoo.com/odoo/tbg/2765?debug=1

Issue
-----
When shipping internationally with Easypost, the currency on the commercial invoice does not always match the one of the sale order.

Steps to reproduce
-----
- Install Easypost
- Create a new pricelist using a different currency from the company
- Create a SO
	- Some product with a weight & HS code
	- Customer must be in another country from company (for commercial invoice)
	- Use the new pricelist
	- Add easypost delivery
- Confirm SO
- Validate linked picking

> Commercial invoice uses company currency instead of SO's

Cause
-----
The currency being sent to Easypost is retrieved from the package in

https://github.com/odoo/enterprise/blob/4c540f450d4de8b59b871662123f85ed54cca2a9/delivery_easypost/models/easypost_request.py#L146

The package object is actually created by calling the carrier's `_get_packages_from_picking` method

https://github.com/odoo/enterprise/blob/4c540f450d4de8b59b871662123f85ed54cca2a9/delivery_easypost/models/easypost_request.py#L266-L270

Solution
-----
We could be fixing this in `stock_delivery` by creating the package with the correct currency when calling `_get_packages_from_picking`. The problem with this approach is that this might negatively affect other carrier services, as discussed in https://github.com/odoo/odoo/pull/268224.

Instead, we can apply a band-aid fix to take the currency from the picking's sale in the `delivery_easypost` module, which is the only one where the problem was reported.

-----
Ticket:
opw-6224883

Forward-Port-Of: odoo/enterprise#123083

When a live chat channel has no operators configured and the chatbot
script ends with a Forward to operator step, triggering that step
causes a traceback.

Steps to reproduce the error:
- Install ``im_livechat`` module with demo data
- Go to Live Chat > Configuration > Chatbots > Create a new chatbot >
  Add script > Step Type: Question > Set answers > Save >
  Add script > Step Type: Forward to operator >
  Only If: Set one of the above answers > Save
- Go to Live chat > Channel > Click the configure channel on YourWebsite.com > Remove the operators > Save
- Go to the chatbot > test > select the configured answer

Traceback:
```py
StopIteration
```

https://github.com/odoo/odoo/blob/8791cdcd89ea3cb56b1fac63b3e2ffbd2956a912/addons/im_livechat/controllers/chatbot.py#L65-L70
When the chatbot script reaches a Forward to operator step while no operator
is configured in the live chat channel, no chatbot message is created.
As a result, the generator iterates over an empty iterator, and
the ``next()`` call raises a ``StopIteration`` exception, causing a traceback
during the conversation.

sentry-7435424405

---
I confirm I have signed the CLA and read the PR guidelines at www.odoo.com/submit-pr

Forward-Port-Of: odoo/odoo#274615
Forward-Port-Of: odoo/odoo#261726

This PR is needed for the fix of https://github.com/odoo/odoo/pull/272411

**Problem:**
lot's standard price are not correct 
when the product is fifo and move have 
different values and multiple lots

**Steps to reproduce:**
- product fifo tracked and valued by lots
- 20 IN @ 100 (all in lot 1)
- 10 IN @ 10 (5 in lot 1 and 5 in lot 2)
- on the product form click on the 
lot/serial number smart button and 
select lot 1

**Current behavior:**
the average cost of lot1 is 64
back on the product form the standard price is 
55

**Expected behavior:**
the average cost of lot 1 should be 20 * 100 (from move1) + 
5 * 10 (from move 2) / 25 = 2050 / 25 = 82
the standard price of the product should be 
2100 / 30 = 70

**Cause of the issue:**
Because the product is fifo, to compute 
the avg_cost of the lot we call _run_fifo()
https://github.com/odoo/odoo/blob/456026b5ef99388b1cf5bdd78cee8d1ad3d51304/addons/stock_account/models/stock_lot.py#L47
which calls _run_fifo_get_stack() to get the fifo
stack specific to this lot.
https://github.com/odoo/odoo/blob/456026b5ef99388b1cf5bdd78cee8d1ad3d51304/addons/stock_account/models/product.py#L545

Issue 1) 
run_fifo_get_stack() stores the on hand quantity (for the lot 
if a lot is given as param) in fifo_stack_size and, 
as long as there is moves and fifo_stack_size>0, 
adds move (starting from the last one in date) to the stack
and removes the quantity of the move from fifo_stack_size.
It then returns the moves stack and the remaning quantity 
on the first move of the stack (for the rest we know it's the 
full quantity)
https://github.com/odoo/odoo/blob/456026b5ef99388b1cf5bdd78cee8d1ad3d51304/addons/stock_account/models/product.py#L612-L618

Inside run_fifo_get_stack(), to do this, because 
we're only considering the quantities from 
this specific lot we should only remove the quantity from 
the move that went in lot, but currently 
we're removing the quantity from the entire move.
https://github.com/odoo/odoo/blob/456026b5ef99388b1cf5bdd78cee8d1ad3d51304/addons/stock_account/models/product.py#L615-L618
So, at the first iteration of the while loop (for the move 
with 10 quantities), instead of doing 
fifo_stack_size(25) -= 5, we do fifo_stack_size(25) -= 10
The next move is the last one, so it's the one on which
remaining_qty_on_first_stack_move will be based on. 
remaining_qty_on_first_stack_move will be the minimum 
between the move's quantity and the fifo_stack_size. 
So because the fifo_stack_size is now wrongfully 
15 instead of 20 that's the value that will be returned
by _run_fifo_get_stack.

So inside run_fifo(), qty_on_first_move will be 15 instead of 20
https://github.com/odoo/odoo/blob/456026b5ef99388b1cf5bdd78cee8d1ad3d51304/addons/stock_account/models/product.py#L545

Issue 2) 
Another issue is that inside _run_fifo when calling
_get_valued on the move, we don't use the lot 
parameter. So we use the entire quantity of the move 
instead of the quantity specific to the lot. 
https://github.com/odoo/odoo/blob/b07ff5843ee87741b293d9e67f72a77a2ed2ed88/addons/stock_account/models/product.py#L561-L562
And we use the full value of the move instead of 
the pro rata of the value for the quantity specific 
to the lot


As a consequence, inside _run_fifo the computation 
for the fifo_cost will be 
15 (because of issue1)  * 100 $ [first iteration of the while loop]
 \+ 10 (because of issue 2) * 10$ [second iteration of the while loop]
= 1600$
Instead of 20 *100 + 5 *10$ = 2050$

Therefore the avg_cost of the lot is wrong and the 
standard price of the product will also be false.

side note: those two issues balance each other if the price unit 
of the moves are the same

needed for PR of opw-6311341

Forward-Port-Of: odoo/odoo#273728