[ADD] website_sale_disable_cart: extract cart restriction from website_sale_aplicoop

The "shop as a read-only catalog" behaviour lived inside website_sale_aplicoop,
so every site that wanted the eskaera flow also lost the standard cart. It now
ships as its own installable addon, with the redirect target configurable
instead of hardcoded to /eskaera.

- website_sale_disable_cart: hides the cart UI (12 header styles + the product
  card quick-add) and overrides the standard cart endpoints. Redirect URL is
  configurable in Website settings (default /shop); only site-internal paths are
  accepted, so a misconfigured value cannot turn the shop into an open redirect
  nor loop back into a disabled route.
- Fixes carried over from the original code: /shop/cart/quantity is the Odoo 18
  path (it was /shop/cart_quantity, which never matched), the boxed, sidebar and
  sales two/three/four headers were not covered (the cart link stayed visible on
  them), and the routes now override the standard methods instead of registering
  duplicate ones.
- website_sale_aplicoop 18.0.1.12.0: drops the view file and the four redirect
  routes; installing it no longer touches the standard shop.

Upgrade order matters: update website_sale_aplicoop first, then install
website_sale_disable_cart in a second Odoo run — both use the same XPaths and
obsolete records are only cleaned up at the end of a run.

Tests: 8/8 in website_sale_disable_cart, aplicoop unaffected (its 2 failures
predate this change). Verified live on a DB clone: /shop/cart returns 303 to the
configured URL and no cart markup remains on /shop.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

website_sale_disable_cart/README.rst

@@ -0,0 +1,106 @@
+===============================
+Website Sale - Disable Cart
+===============================
+
+.. image:: https://img.shields.io/badge/license-AGPL--3-blue.svg
+   :target: https://www.gnu.org/licenses/agpl-3.0-standalone.html
+   :alt: License: AGPL-3
+.. image:: https://img.shields.io/badge/Odoo-18.0-blue
+   :alt: Odoo: 18.0
+
+Turn the standard Odoo eCommerce shop into a **read-only product catalog**:
+visitors can browse, search and open product pages, but the standard
+``website_sale`` shopping cart is not reachable any more.
+
+It is meant for sites where the actual ordering happens somewhere else — for
+example the group order flow of ``website_sale_aplicoop`` (``/eskaera``), a
+quotation request form, or an offline/phone process — while the public shop is
+still useful as a catalog.
+
+What the module does
+====================
+
+- Hides the cart link and badge from all 12 standard website header styles
+  (default, mobile, hamburger, stretch, vertical, search, boxed, sidebar and
+  sales one to four).
+- Removes the "Add to cart" quick-add area from the product listing cards.
+- Neutralizes the standard cart endpoints:
+
+  - ``/shop/cart`` and ``/shop/cart/update`` redirect to a configurable URL.
+  - ``/shop/cart/update_json`` returns an empty payload (no cart is written).
+  - ``/shop/cart/quantity`` always returns ``0``.
+  - ``/shop/cart/clear`` does nothing.
+
+Only the **cart** is disabled. Product listing, search, product pages and the
+rest of ``website_sale`` are untouched. Checkout and payment routes are left
+untouched too; with an empty cart they redirect back to the cart route, and
+therefore to the configured URL.
+
+Configuration
+=============
+
+Go to *Website > Configuration > Settings > Disabled Cart* and set
+**Cart Redirect URL**: the internal path visitors land on when they reach a
+standard cart URL.
+
+- Default: ``/shop``.
+- Stored in the system parameter ``website_sale_disable_cart.redirect_url``.
+- Only site-internal paths are accepted. Absolute URLs (``https://...``) and
+  protocol relative URLs (``//host/path``) are ignored — otherwise the shop
+  could be used as an open redirect — as is any path under ``/shop/cart``,
+  which would loop back into a disabled route. In those cases ``/shop`` is
+  used and a warning is logged.
+
+Example: on a site running ``website_sale_aplicoop``, set it to ``/eskaera`` so
+that every standard cart URL lands on the group order flow.
+
+Usage
+=====
+
+There is nothing to do at runtime: once installed, the cart is disabled site
+wide. To go back to the standard behaviour, uninstall the module — all template
+modifications are removed with it and the ``website_sale`` cart works again as
+usual.
+
+Files involved
+==============
+
+- ``controllers/website_sale.py`` — overrides the ``website_sale`` cart routes.
+- ``views/website_sale_disable_cart_templates.xml`` — templates that hide the
+  cart UI.
+- ``models/res_config_settings.py`` and ``views/res_config_settings_views.xml``
+  — the redirect URL setting.
+
+Installation
+============
+
+::
+
+    docker-compose run --rm odoo odoo -d odoo -i website_sale_disable_cart --stop-after-init
+    docker-compose up -d
+
+Testing
+=======
+
+::
+
+    docker-compose run --rm odoo odoo -d odoo --test-enable --stop-after-init -u website_sale_disable_cart
+
+Credits
+=======
+
+**Authors:**
+
+* Criptomart
+
+**History:**
+
+This behaviour was originally implemented inside ``website_sale_aplicoop`` and
+was extracted into this module so that it can be installed and configured
+independently of the group order flow.
+
+License
+=======
+
+AGPL-3. See ``LICENSE.txt`` or
+https://www.gnu.org/licenses/agpl-3.0-standalone.html