chore: remove RST swap mechanism, archive rst-*.rst under docs/_rst_legacy/

The swap mechanism (RST-as-fallback for migrated MD pages) is dormant —
docs/_rst_overrides.txt has been empty since the MyST flip trio
(#1899/#1900/#1901) landed. The mechanism's surface area is dead weight
and the rst-*.rst shadows scattered across the source tree cause
Context7's parser to misclassify the project as RST.

Sibling PR on rolling: yuriy/remove-rst-swap-mechanism

Changes:
- Move 253 rst-*.rst shadow files into docs/_rst_legacy/ preserving
  subdirectory structure. They remain in the repo for reference; Sphinx
  excludes the folder via exclude_patterns.
- Strip swap_sources.py invocation from docs/Makefile.
- Strip jobs: pre_build/post_build block from .readthedocs.yml.
- Strip rst-*.rst exclude entry and the _md_exclude.txt loader from
  docs/conf.py; replace with a single _rst_legacy exclude.
- Delete scripts/swap_sources.py, tests/test_swap_sources.py,
  docs/_rst_overrides.txt.
- Update AGENTS.md: drop the "RST override mechanism" section and the
  test-runner snippet for the deleted test.

Verified: sphinx-build -b html with --keep-going produces identical
warning set (68 unique), identical sitemap entry count (267), identical
llms.txt entry count (22), zero rst-* URLs in any artifact.

🤖 Generated by [robots](https://vyos.io)

5 files changed, 0 insertions, 338 deletions

diff --git a/docs/installation/cloud/rst-aws.rst b/docs/installation/cloud/rst-aws.rst
deleted file mode 100644
index 2901b6d1..00000000
--- a/docs/installation/cloud/rst-aws.rst
+++ /dev/null
@@ -1,166 +0,0 @@
-:lastproofread: 2026-02-06
-
-##########
-Amazon AWS
-##########
-
-Deploy VM
----------
-
-Deploy VyOS on Amazon :abbr:`AWS (Amazon Web Services)`.
-
-1. Click **Instances** and then click **Launch Instance**.
-
-.. figure:: /_static/images/cloud-aws-01.png
-
-2. Search for "VyOS" in the Marketplace.
-
-.. figure:: /_static/images/cloud-aws-02.png
-
-3. Choose the instance type. The recommended minimum is ``m3.medium``.
-
-.. figure:: /_static/images/cloud-aws-03.png
-
-4. Configure the instance for your requirements. Select the number of
-   instances, network, and subnet.
-
-.. figure:: /_static/images/cloud-aws-04.png
-
-5. Configure additional storage. You can remove the additional storage
-   ``/dev/sdb``. The root device will be ``/dev/xvda``. You can skip this step.
-
-.. figure:: /_static/images/cloud-aws-05.png
-
-6. Configure the security group. We recommend configuring SSH access
-   only from specific sources, or you can permit any IP address (the default).
-
-.. figure:: /_static/images/cloud-aws-06.png
-
-7. Select the SSH key pair and click **Launch Instances**.
-
-.. figure:: /_static/images/cloud-aws-07.png
-
-8. Note your public IP address.
-
-.. figure:: /_static/images/cloud-aws-08.png
-
-9. Connect to the instance using your SSH key.
-
-  .. code-block:: none
-
-    ssh -i ~/.ssh/amazon.pem vyos@203.0.113.3
-    vyos@ip-192-0-2-10:~$
-
-Amazon CloudWatch Agent Usage
------------------------------
-
-To use the Amazon CloudWatch agent, configure it in the Amazon Systems Manager
-Parameter Store. For instructions on creating a configuration, see
-:ref:`configuration_creation`.
-
-1. Create an :abbr:`IAM (Identity and Access Management)` role for the
-   :abbr:`EC2 (Elastic Compute Cloud)` instance to access CloudWatch service,
-   and name it CloudWatchAgentServerRole. The role should contain two default
-   policies: ``CloudWatchAgentServerPolicy`` and
-   ``AmazonSSMManagedInstanceCore``.
-
-2. Attach the created role to your VyOS :abbr:`EC2 (Elastic Compute Cloud)`
-   instance.
-
-3. Ensure the amazon-cloudwatch-agent package is installed. 
-
-  .. code-block:: none
-
-    $ sudo apt list --installed | grep amazon-cloudwatch-agent
-
-  .. note:: The amazon-cloudwatch-agent package is normally included in
-     VyOS 1.3.3+ and 1.4+
-
-4. Retrieve an existing CloudWatch Agent configuration from the
-   :abbr:`SSM (Systems Manager)` Parameter Store.
-
-  .. code-block:: none
-
-    $ sudo /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -s -c ssm:<your-configuration-name>
-
-  This step also enables systemd service and runs it.
-
-  .. note:: The VyOS platform-specific scripts feature is under development.
-     Thus, this step should be repeated manually after changing system image
-     (:doc:`/installation/update`)
-
-.. _configuration_creation:
-
-CloudWatch SSM Configuration creation
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Creating the Amazon Cloudwatch Agent Configuration in Amazon
-:abbr:`SSM (Systems Manager)` Parameter Store.
-
-1. Create an :abbr:`IAM (Identity and Access Management)` role for your
-   :abbr:`EC2 (Elastic Compute Cloud)` instance to access the CloudWatch
-   service. Name it ``CloudWatchAgentAdminRole``. The role must contain at
-   least two policies: ``CloudWatchAgentAdminPolicy`` and
-   ``AmazonSSMManagedInstanceCore``.
-
-  .. note:: CloudWatchAgentServerRole is too permissive and should be used only
-     for
-     creating and deploying a single configuration. After step 3, we recommend
-     replacing the ``CloudWatchAgentAdminRole`` with the 
-     ``CloudWatchAgentServerRole``.
-
-2. Run the CloudWatch configuration wizard.
-
-  .. code-block:: none
-
-    $ sudo /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-config-wizard
-
-3. When prompted, enter "yes" to the question "Do you want to store the
-   config in the SSM parameter store?".
-
-AWS Gateway Load Balancer
---------------------------
-
-VyOS supports the AWS Gateway Load Balancer (GWLB) tunnel handler (``gwlbtun``),
-which enables VyOS to act as an inspection or processing target for GWLB. GWLB
-uses Geneve encapsulation with custom metadata to deliver traffic to VyOS for
-packet filtering, shaping, deep packet inspection, NAT, or other traffic
-manipulation functions. The tunnel handler automatically creates Linux tunnel
-interfaces (``gwi-*`` for ingress and ``gwo-*`` for egress) per endpoint,
-allowing you to use standard Linux utilities like iptables, tc, and netfilter
-to implement your inspection or processing logic. This enables VyOS to serve as
-a centralized appliance for traffic inspection in your AWS infrastructure,
-supporting both single-endpoint (1-arm) and multi-endpoint (2-arm) deployment
-modes.
-
-.. stop_vyoslinter
-For more information about integrating with AWS Gateway Load Balancer, see
-the following article from AWS:
-`How to integrate Linux instances with AWS Gateway Load Balancer <https://aws.amazon.com/blogs/networking-and-content-delivery/how-to-integrate-linux-instances-with-aws-gateway-load-balancer/>`__.
-
-.. start_vyoslinter
-Configuration Example
-^^^^^^^^^^^^^^^^^^^^^
-
-Configure the AWS GWLB service with the following commands:
-
-.. code-block:: none
-
-  set service aws glb script on-create '/config/scripts/glb-create.sh'
-  set service aws glb script on-destroy '/config/scripts/glb-destroy.sh'
-  set service aws glb status format 'simple'
-  set service aws glb status port '8282'
-  set service aws glb threads tunnel '4'
-  set service aws glb threads tunnel-affinity '1-2'
-  set service aws glb threads udp '4'
-  set service aws glb threads udp-affinity '0-3'
-
-.. stop_vyoslinter
-References
-----------
-- https://console.aws.amazon.com/
-- https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/create-iam-roles-for-cloudwatch-agent.html
-- https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/install-CloudWatch-Agent-on-EC2-Instance-fleet.html
-- https://aws.amazon.com/blogs/networking-and-content-delivery/how-to-integrate-linux-instances-with-aws-gateway-load-balancer/
-
-.. start_vyoslinter
diff --git a/docs/installation/cloud/rst-azure.rst b/docs/installation/cloud/rst-azure.rst
deleted file mode 100644
index 77d00814..00000000
--- a/docs/installation/cloud/rst-azure.rst
+++ /dev/null
@@ -1,84 +0,0 @@
-:lastproofread: 2026-02-09
-
-#####
-Azure
-#####
-
-Deploy VM
----------
-
-Deploy VyOS on Azure.
-
-1. Go to Azure services and click **Add new Virtual machine**.
-
-2. Choose a VM name, resource group, and region, then click **Browse all public 
-   and private images**.
-
-.. figure:: /_static/images/cloud-azure-01.png
-
-3. Search for "VyOS" in the marketplace and choose the appropriate 
-   subscription.
-
-.. figure:: /_static/images/cloud-azure-02.png
-
-4. Generate new SSH key pair or use existing.
-
-.. figure:: /_static/images/cloud-azure-03.png
-
-5. Configure the network, subnet, and public IP. Or use the defaults.
-
-.. figure:: /_static/images/cloud-azure-04.png
-
-6. Click **Review + create**. Your deployment completes in a few seconds.
-
-.. figure:: /_static/images/cloud-azure-05.png
-
-7. Select your new VM and note your public IP address.
-
-.. figure:: /_static/images/cloud-azure-06.png
-
-8. Connect to the instance with your SSH key.
-
-  .. code-block:: none
-
-    ssh -i ~/.ssh/vyos_azure vyos@203.0.113.3
-    vyos@vyos-doc-r1:~$
-
-Add interface
--------------
-
-If your instance was deployed with one **eth0** (``WAN``) interface and you
-want to add another, you must shut down the instance. To add a new interface,
-such as **eth1** (``LAN``), attach it in the Azure portal and then restart the
-instance.
-
-.. note:: Azure doesn't allow you to attach an interface while the instance is
-   running.
-
-Absorbing Routes
-----------------
-
-If you're using the VM as a router, you can use a route table to absorb some or
-all traffic from your virtual network (VNET) with your LAN interface.
-
-1. Create a route table and navigate to **Configuration**.
-
-2. Add one or more routes for the networks you want to route through the VyOS
-   VM. For **Next hop type**, select **Virtual Appliance** and set the **Next
-   Hop Address** to the VyOS ``LAN`` interface.
-
-.. note:: To create a default route for VMs on the subnet, use
-   **Address Prefix** ``0.0.0.0/0``. For a typical edge device configuration,
-   configure masquerade NAT on the ``WAN`` interface.
-
-Serial Console
---------------
-
-VyOS includes serial console support by default. However, if you replace the
-``config.boot`` file and reboot, ensure this configuration is present:
-
-``set system console device ttyS0 speed '9600'``
-
-References
-----------
-https://azure.microsoft.com
diff --git a/docs/installation/cloud/rst-gcp.rst b/docs/installation/cloud/rst-gcp.rst
deleted file mode 100644
index f6b6732b..00000000
--- a/docs/installation/cloud/rst-gcp.rst
+++ /dev/null
@@ -1,59 +0,0 @@
-:lastproofread: 2026-02-09
-
-#####################
-Google Cloud Platform
-#####################
-
-Deploy VM
----------
-
-To deploy VyOS on Google Cloud Platform (GCP):
-
-1. Generate an SSH key pair of type **ssh-rsa** on the host that will connect
-   to VyOS.
-
-   Example:
-
-   .. code-block:: none
-
-     ssh-keygen -t rsa -f ~/.ssh/vyos_gcp -C "vyos@mypc"
-
-.. note:: The SSH key comment must begin with ``vyos@`` because that's the
-   default VyOS user. GCP uses this value to set the username on the instance.
-
-
-2. Open the GCP Console and navigate to **Metadata**. Select **SSH Keys** and 
-   click **Edit**.
-
-.. figure:: /_static/images/cloud-gcp-01.png
-
-
-   Click **Add item**, paste your public SSH key, and click **Save**.
-
-.. figure:: /_static/images/cloud-gcp-02.png
-
-
-3. Search for "VyOS" in the Marketplace.
-
-4. Configure the deployment name, zone, and machine type, then click **Deploy**.
-
-.. figure:: /_static/images/cloud-gcp-03.png
-
-5. After a few seconds, select your **instance**.
-
-.. figure:: /_static/images/cloud-gcp-04.png
-
-6. Note your external IP address.
-
-.. figure:: /_static/images/cloud-gcp-05.png
-
-7. Connect to the instance using the SSH key you generated in step 1.
-
-  .. code-block:: none
-
-    ssh -i ~/.ssh/vyos_gcp vyos@203.0.113.3
-    vyos@vyos-r1-vm:~$
-
-References
-----------
-https://console.cloud.google.com/
diff --git a/docs/installation/cloud/rst-index.rst b/docs/installation/cloud/rst-index.rst
deleted file mode 100644
index 18d525ac..00000000
--- a/docs/installation/cloud/rst-index.rst
+++ /dev/null
@@ -1,11 +0,0 @@
-##################
-Cloud Environments
-##################
-
-.. toctree::
-   :caption: Content
-
-   aws
-   azure
-   gcp
-   oracle
diff --git a/docs/installation/cloud/rst-oracle.rst b/docs/installation/cloud/rst-oracle.rst
deleted file mode 100644
index f5e03329..00000000
--- a/docs/installation/cloud/rst-oracle.rst
+++ /dev/null
@@ -1,18 +0,0 @@
-:lastproofread: 2026-02-09
-
-######
-Oracle
-######
-
-.. note:: This page is a stub and needs expansion.
-   Contributions welcome via the
-   VyOS `documentation repository`_.
-
-.. _documentation repository: https://github.com/vyos/vyos-documentation
-
-.. stop_vyoslinter
-References
-----------
-https://www.oracle.com/cloud/
-https://docs.oracle.com/en/cloud/paas/developer-cloud-classic/csdcc/deploy-application.html
-.. start_vyoslinter