feat: flip swap mechanism — MD as primary, RST as override (Phase 1)

This is the first of three phases inverting the per-page swap mechanism
so MD becomes the canonical primary and RST becomes the rare override.

Phase 1 — file renames + conf.py exclude_patterns flip only:
- Rename docs/**/md-<stem>.md to docs/**/<stem>.md (drop md- prefix)
  for all 254 stems previously listed in docs/_swap.txt
- Rename docs/**/<stem>.rst to docs/**/rst-<stem>.rst (add rst- prefix)
  for the same 254 stems
- Repurpose docs/_swap.txt as docs/_rst_overrides.txt; initially empty
  comment-only since no pages need the RST fallback right now
- conf.py exclude_patterns flipped: rst-*.rst is now excluded by default
  instead of md-*.md
- conf.py runtime-artifact references updated to _rst_override_state.json
  and _md_exclude.txt (Phase 2 will rewrite swap_sources.py to produce
  these names; for now no swap script runs because overrides list is empty)

Phase 2 (next commit on this branch) will rewrite scripts/swap_sources.py
with inverted rename direction, delete scripts/import_myst.py + tests, and
update tests/test_swap_sources.py for the new semantics.

Phase 3 will be the cleanup pass and ready-for-review flip.

Generated by robots https://vyos.io

1 files changed, 106 insertions, 0 deletions

diff --git a/docs/operation/information.md b/docs/operation/information.md
new file mode 100644
index 00000000..a6b6de0c
--- /dev/null
+++ b/docs/operation/information.md
@@ -0,0 +1,106 @@
+---
+lastproofread: '2025-11-19'
+---
+
+(information)=
+
+# System Information
+
+VyOS features a rich set of operational level commands to retrieve arbitrary
+information about your running system. For more information on the VyOS command
+line interface (CLI), see {ref}`cli`.
+
+# Hardware
+
+(hardware_usb)=
+
+## USB
+
+In the past, serial interfaces were defined as `ttySx` and `ttyUSBx` where
+`x` was the instance number. However, the mapping of USB-based
+serial interfaces can change from one system boot to another, depending on
+which driver the operating system loads first.
+This inconsistency can be problematic when you
+use multiple serial interfaces.
+For example, both console-server connections and a serial-backed
+{ref}`wwan-interface`.
+
+To address this issue, and because many low-cost USB-to-serial converters
+do not have a programmed serial number, VyOS now identifies USB-to-serial
+interfaces by the USB root bridge and the bus they connect to.
+This approach is similar to the network interface naming conventions used in
+recent Linux distributions.
+
+```{opcmd} show hardware usb
+
+Retrieve a tree-like representation of all connected USB devices.
+
+:::{note}
+If a device is unplugged and plugged in again, it is assigned a new
+``Port``, ``Dev``, and ``If``.
+:::
+```
+
+```{opcmd} show hardware usb serial
+
+Retrieve a list and description of all connected USB serial devices. The
+device name displayed, (for example ``usb0b2.4p1.0``), can be used
+directly when accessing the serial console as console-server device.
+```
+
+(information-version)=
+
+# Version
+
+```{opcmd} show version
+
+Return the currently running VyOS version and build information. This
+includes the name of the release train, e.g., ``sagitta`` on VyOS 1.4,
+and ``circinus`` on VyOS 1.5.
+
+:::{code-block} none
+vyos@vyos:~$ show version
+
+Version:          VyOS 1.4-rolling-202106270801
+Release Train:    sagitta
+
+Built by:         autobuild@vyos.net
+Built on:         Sun 27 Jun 2021 09:50 UTC
+Build UUID:       ab43e735-edcb-405a-9f51-f16a1b104e52
+Build Commit ID:  f544d75eab758f
+
+Architecture:     x86_64
+Boot via:         installed image
+System type:      KVM guest
+
+Hardware vendor:  QEMU
+Hardware model:   Standard PC (i440FX + PIIX, 1996)
+Hardware S/N:
+Hardware UUID:    Unknown
+
+Copyright:        VyOS maintainers and contributors
+:::
+```
+
+```{opcmd} show version kernel
+
+Return the version number of the currently running Linux kernel.
+
+:::{code-block} none
+vyos@vyos:~$ show version kernel
+5.10.46-amd64-vyos
+:::
+```
+
+```{opcmd} show version frr
+
+Return the version number of FRR (Free Range Routing - <https://frrouting.org/>)
+used in this release. This is the routing control plane and a successor to GNU
+Zebra and Quagga.
+
+:::{code-block} none
+vyos@vyos:~$ show version frr
+  FRRouting 7.5.1-20210625-00-gf07d935a2 (vyos).
+  Copyright 1996-2005 Kunihiro Ishiguro, et al.
+:::
+```