docs(development): refresh e2e testing guide for the Chainsaw migration

content/en/docs/next/development.md

@@ -348,40 +348,35 @@ Feel free to look inside each Makefile to better understand the logic.
 
 ### Testing
 
-The platform includes an [`e2e.sh`](https://github.com/cozystack/cozystack/blob/main/hack/e2e.sh) script that performs the following tasks:
+End-to-end tests run against a cluster that lives in a **sandbox container**. The sandbox is a privileged Docker container on the machine where you run `make`, and it starts three QEMU virtual machines with KVM. A run has three stages: preparing the cluster (VMs and Talos Linux), installing Cozystack, and running the tests. The suite has two parts:
 
-- Runs three QEMU virtual machines
-- Configures Talos Linux
-- Installs Cozystack
-- Waits for all HelmReleases to be installed
-- Performs additional checks to ensure that components are up and running
+- **Application tests** — [Kyverno Chainsaw](https://kyverno.github.io/chainsaw/) suites under [`hack/e2e-chainsaw/`](https://github.com/cozystack/cozystack/tree/main/hack/e2e-chainsaw), one directory per application, each with a `chainsaw-test.yaml`.
+- **Bootstrap and API tests** — BATS scripts: `hack/e2e-prepare-cluster.bats` boots the VMs and configures Talos, `hack/e2e-install-cozystack.bats` installs Cozystack on that cluster, and `hack/e2e-test-openapi.bats` checks the aggregated API.
 
-You can run e2e.sh either locally or directly within a Kubernetes container.
+Conventions for writing and stabilizing these tests live in the [E2E testing guide](https://github.com/cozystack/cozystack/blob/main/docs/agents/e2e-testing.md).
 
-To run tests in a Kubernetes cluster, navigate to the `packages/core/testing` directory and execute the following commands:
+To run the tests, execute the following commands from the root of the repository, in this order:
 
 ```shell
-make apply    # Create testing sandbox in Kubernetes cluster
-make test     # Run the end-to-end tests in existing sandbox
-make delete   # Remove testing sandbox from Kubernetes cluster
+make assets-talos                                # Build the Talos disk image the VMs boot from (_out/assets/nocloud-amd64.raw.xz)
+make prepare-env                                 # Start the sandbox container, boot the VMs and configure Talos
+make -C packages/core/testing install-cozystack  # Install Cozystack in the cluster
+make -C packages/core/testing e2e                # Run the end-to-end tests (OpenAPI + Chainsaw)
+make -C packages/core/testing delete             # Remove the sandbox container
 ```
 
+The root `make test` is `apply` followed by `e2e`. It starts an empty sandbox and never creates the cluster, so it is not a shortcut for the commands above.
+
 {{% alert color="warning" %}}
-:warning: To run e2e tests in a Kubernetes cluster, your nodes must have sufficient free resources to create 3 VMs and store the data for the deployed applications.
+:warning: To run e2e tests, the machine that runs Docker must support KVM and have enough free resources for 3 VMs and the data of the deployed applications. By default each VM gets 8 vCPUs and 24 GiB of memory.
 
-It is recommended to use bare-metal nodes of the parent Cozystack cluster.
+A bare-metal machine is recommended.
 {{% /alert %}}
 
 ### Dynamic Development Environment
 
-If you prefer to develop Cozystack in virtual machines instead of modifying the existing cluster, you can utilize the same sandbox from testing environment. The Makefile in the `packages/core/testing` includes additional options:
+If you prefer to develop Cozystack against the sandbox instead of modifying the existing cluster, open an interactive shell inside the running sandbox container from the `packages/core/testing` directory:
 
 ```shell
 make exec     # Opens an interactive shell in the sandbox container.
-make login    # Downloads the kubeconfig into a temporary directory and runs a shell with the sandbox environment; mirrord must be installed.
-make proxy    # Enable a SOCKS5 proxy server; mirrord and gost must be installed.
 ```
-
-Socks5 proxy can be configured in a browser to access services of a cluster running in sandbox. Firefox has a handy extension for toogling proxy on/off:
-
-- [Proxy Toggle](https://addons.mozilla.org/en-US/firefox/addon/proxy-toggle/)