Steps to reproduce the bug:
- Install point_of_sale
- Open the POS frontend and create a new product from the register
- Add it to the order, then open its product info popup and edit it
    - Rename it and change its price
- Confirm the edit dialog
- Click on the (renamed) product again to add it to the order

Problem:
On runbot the tour test_product_create_update_from_frontend (point_of_sale/tests/test_frontend.py, MobileTestUi) intermittently times out waiting for the orderline to show the edited product name/quantity/ price combination.

editProduct()'s onSave callback in pos_store.js closed the edit dialog via act_window_close right after firing this.data.read("product.template", ...) and this.data.searchRead("product.product", ...), without waiting for either call to resolve. When the dialog closes before those RPCs land, the in-memory product record used by canBeMergedWith() (pos_order_line.js) to decide how to merge/create the next orderline can still hold the stale price, so re-clicking the product right after editing produces an orderline that never matches the expected quantity/price.

Solution:
Make onSave async and await both this.data.read() and this.data.searchRead() before closing the dialog, so the reactive store is guaranteed to hold the updated product data before the user (or the tour) can interact with the product again.

runbot-223630

Forward-Port-Of: odoo/odoo#277698

**Description of the issue/feature this PR addresses:**

When adding a custom field (e.g., via Studio) to the Documents list view, clicking the cell directly does not trigger inline edit mode. The user has to first click a standard editable field (like "Owner") to put the row into edit mode before they can modify the custom field.

This occurs because we use a hardcoded whitelist (`editableColumns`) of standard fields allowed to trigger edit mode. Custom fields (`x_`) are missing from this static list.

This commit resolves the issue by dynamically injecting visible, non-readonly custom fields into the `editableColumns` whitelist. This allows user-created fields to be edited inline as expected.

**Steps to reproduce:**

- Documents > Studio > List view > Add any field that accepts user input (e.g. Text/char) > save/exit
- In the same Documents list view > select a row > click the cell belonging to the newly created field > observe that the row does not enter edit mode
- In the same Documents list view > select a row > click a standard editable cell, then click the cell belonging to our newly created field > observe that this then allows us to edit our field

**Current behavior before PR:**

- Custom fields do not trigger inline edit mode

**Desired behavior after PR is merged:**

- Custom fields trigger inline edit mode

opw-6378102

Forward-Port-Of: odoo/enterprise#125239

Steps to reproduce:
- Configure a preparation display on a POS config with a product category
- Place an order and leave it in a non-final stage
- Keep the session open past midnight

Issue:
The kanban order-count badge drops the order once its create_date falls behind "today", while the preparation screen still lists it. The same divergence makes the badge keep counting an order that a "Reset" already removed from the screen.

_compute_order_count() scoped its search on pos_config_id and create_date >= today, whereas the screen is built by get_preparation_display_order() from _get_open_orders_in_display() and _get_stageless_orders_in_display(), which have no date filter and instead bound the set by the order stage `done` flag and the session state. An order open across midnight is therefore in the screen set but not in the badge set. Conversely reset() marks the current stage done, which drops the order from the screen set, but the badge only skipped orders whose latest stage is the final stage, so an order reset while still in the first stage stayed counted.

opw-6414302

Forward-Port-Of: odoo/enterprise#126139
Forward-Port-Of: odoo/enterprise#125984

**Problem:**
When an appointment is cancelled, the cancellation email is always sent in the organizer's (staff member's) language, ignoring the booking customer's language. The booking confirmation, by contrast, is correctly localized.

**Steps to reproduce:**
1. Set a contact's language to a non-default one (e.g. Romanian).
2. Book an appointment for that contact (they are the booker/attendee).
3. Cancel the appointment.
4. The customer received the confirmation in Romanian but the cancellation email arrives in English.

**Current behavior:**
The cancellation email is rendered in the organizer's language.

**Expected behavior:**
The cancellation email is rendered in the booking customer's language, like the confirmation/invitation email.

**Cause of the issue:**
The cancellation uses `appointment_canceled_mail_template`, whose `lang` is `{{ object.partner_id.lang }}`. On `calendar.event`, `partner_id` is `related='user_id.partner_id'`, i.e. the organizer, not the customer. The template is posted once per event (via `_track_template`), so its single rendering language applies to every recipient, including attendees whose own language differs. The confirmation email is unaffected because it is the per-attendee `attendee_invitation_mail_template` (model `calendar.attendee`), rendered once per attendee in that attendee's language.

**Fix:**
Deriving the language from `appointment_booker_id` makes the cancellation consistent with the other appointment mails, which are meant for the person who booked the meeting. It falls back to `partner_id` when there is no booker (e.g. an event not created through the appointment flow), preserving the previous behavior in that case.

opw-6323179

Forward-Port-Of: odoo/enterprise#124116