feat: flip swap mechanism on circinus — MD as primary, RST as override

Mirror of #1899 for circinus. Same logic, same scripts, per-branch file set.

Changes:
- Rename docs/**/md-<stem>.md to docs/**/<stem>.md (drop md- prefix) for
  all 253 stems previously listed in docs/_swap.txt
- Rename docs/**/<stem>.rst to docs/**/rst-<stem>.rst (add rst- prefix)
  for the same 253 stems
- Repurpose docs/_swap.txt as docs/_rst_overrides.txt; initially empty
- conf.py exclude_patterns flipped: rst-*.rst excluded by default
- conf.py runtime-artifact references updated to _rst_override_state.json
  and _md_exclude.txt
- scripts/swap_sources.py rewritten with inverted rename direction
  (rst-<stem>.rst → <stem>.rst when applying overrides; <stem>.md
  excluded via _md_exclude.txt)
- scripts/import_myst.py and tests/test_import_myst.py deleted (obsolete)
- tests/test_swap_sources.py rewritten for new semantics

Identical change set to #1899 (current). Per-branch differences:
- circinus has 253 stems vs current's 254 (suricata is current-only)
- otherwise the script/conf.py/test changes are byte-identical with current

Generated by robots https://vyos.io

1 files changed, 0 insertions, 204 deletions

diff --git a/docs/contributing/md-debugging.md b/docs/contributing/md-debugging.md
deleted file mode 100644
index d3b4b513..00000000
--- a/docs/contributing/md-debugging.md
+++ /dev/null
@@ -1,204 +0,0 @@
----
-lastproofread: '2025-12-05'
----
-
-(debugging)=
-
-# Debugging
-
-Two flags are available to help debug configuration scripts. Configuration
-loading issues manifest during boot, so these flags are passed as kernel boot
-parameters.
-
-## ISO image build
-
-If you have trouble compiling your own ISO image or debugging Jenkins issues,
-follow the steps at {ref}`iso_build_issues`.
-
-## System Startup
-
-Debug system startup by examining the configuration file loading from
-`/config/config.boot`. Extend the kernel command-line in the bootloader to
-enable this.
-
-### Kernel
-
-- `vyos-debug` - Add this parameter to the Linux boot line to produce
-  timing results for script execution during commit. If you see an unexpected
-  delay during manual or boot commit, this parameter helps identify bottlenecks.
-  The internal flag is `VYOS_DEBUG`, found in [vyatta-cfg]. Output is directed
-  to `/var/log/vyatta/cfg-stdout.log`.
-- `vyos-config-debug` - During development, coding errors can cause commit
-  failures on boot, potentially preventing CLI initialization. This kernel boot
-  parameter ensures access to the system as user `vyos` and logs a Python
-  stack trace to `/tmp/boot-config-trace`. The file is created only if the
-  configuration load fails.
-
-## Live System
-
-Several flags can be set to change VyOS behavior at runtime. Toggle these flags
-using environment variables or by creating files.
-
-For each feature, create a file called `vyos.feature.debug` to enable it.
-If a parameter is required, place it as the first line inside the file.
-
-Place the file in `/tmp` for one-time debugging (the file is removed on
-reboot) or in `/config` to persist permanently.
-
-For example, `/tmp/vyos.ifconfig.debug` can be created to enable
-interface debugging.
-
-You can also enable debugging using environment variables.
-The environment variable name follows the convention `VYOS_FEATURE_DEBUG`.
-
-For example, `export VYOS_IFCONFIG_DEBUG=""` in your vbash has the same effect
-as `touch /tmp/vyos.ifconfig.debug`.
-
-- `ifconfig` - Display all commands and their responses from the OS on
-  screen for inspection.
-- `command` - Display all commands and their responses from the OS on screen
-  for inspection.
-- `developer` - When a command fails, start a PDB post-mortem session instead
-  of showing a standard error message. This allows developers to debug issues
-  interactively. Because the debugger waits for input, it can prevent the router
-  from booting, so only enable this permanently on production systems if you are
-  ready for potential boot failures.
-- `log` - Send all commands used by VyOS to a log file for inspection. This
-  is useful in rare cases when you need to see what the OS is doing, including
-  during boot. The default file is `/tmp/full-log`, but you can change it.
-
-:::{note}
-To retrieve debug output on the command line, disable `vyos-configd`
-in addition. You can do this one-time with
-`sudo systemctl stop vyos-configd`
-or permanently with `sudo systemctl disable vyos-configd`.
-:::
-
-### FRR
-
-Recent versions use the `vyos.frr` framework. The Python class is located in
-`vyos-1x:python/vyos/frr.py`. It includes an embedded debugger similar to the
-one in `vyos.ifconfig`.
-
-Enable debugging by running: `touch /tmp/vyos.frr.debug`
-
-### Debug Python code with PDB
-
-Sometimes it is useful to debug Python code interactively on the live system
-rather than in an IDE. You can do this using pdb.
-
-Assuming you want to debug a Python script called by an op-mode command, find
-the script by looking up the op-mode definitions, then edit it on the live
-system using vi:
-`vi /usr/libexec/vyos/op_mode/show_xyz.py`
-
-Insert the following statement right before the section where you want to
-investigate a problem (for example, a statement you see in a backtrace):
-`import pdb; pdb.set_trace()`
-
-Optionally, surround this statement with an `if` condition that triggers only
-for the conditions you are interested in.
-
-When you run `show xyz` and your condition triggers, you enter the Python
-debugger:
-
-```none
-> /usr/libexec/vyos/op_mode/show_nat_translations.py(109)process()
--> rule_type = rule.get('type', '')
-(Pdb)
-```
-
-You can type `help` to get an overview of the available commands, and
-`help command` to get more information on each command.
-
-Common useful commands include:
-
-- examine variables using `pp(var)`
-- continue execution using `cont`
-- get a backtrace using `bt`
-
-### Config Migration Scripts
-
-Starting with VyOS 1.5, a new mechanism is used for config migration that
-improves migration performance. New migrators use only the new format with a
-`migration()` function.
-
-```python
-from vyos.configtree import ConfigTree
-base = ['vpn', 'ipsec']
-def migrate(config: ConfigTree) -> None:
-    if not config.exists(base):
-        # Nothing to do
-        return
-    # do your stuff here
-```
-
-New-style migration scripts can no longer run on their own. However, the new
-migration subsystem handler includes a test kit:
-
-```none
-vyos@vyos:~$ /usr/libexec/vyos/run-config-migration.py --help
-usage: run-config-migration.py [-h] [--test-script TEST_SCRIPT] [--output-file OUTPUT_FILE] [--force] config_file
-
-positional arguments:
-  config_file           configuration file to migrate
-
-options:
-  -h, --help            show this help message and exit
-  --test-script TEST_SCRIPT
-                        test named script
-  --output-file OUTPUT_FILE
-                        write to named output file instead of config file
-  --force               force run of all migration scripts
-```
-
-To test your migration, run:
-
-```none
-vyos@vyos:~$ /usr/libexec/vyos/run-config-migration.py --test-script /opt/vyatta/etc/config-migrate/migrate/quagga/11-to-12 --output-file /tmp/foo /tmp/static-route-basic
-vyos@vyos:~$ cat /tmp/foo
-```
-
-The file `/tmp/foo` contains the migrated configuration.
-
-### Configuration Error on System Boot
-
-Running the latest rolling releases sometimes exposes bugs due to edge cases
-missed in design. File these bugs via [Phabricator](https://vyos.dev/), but you can help narrow
-down the issue by following these steps:
-
-1. Log in to your VyOS system.
-2. Enter configuration mode: `configure`
-3. Reload your boot configuration: `load`
-
-You should see a Python backtrace that helps identify the issue. Attach it to
-the [Phabricator](https://vyos.dev/) task.
-
-### Boot Timing
-
-During the migration and rewrite of functionality from Perl to Python, system
-boot time increased significantly. You can analyze and graph boot time to see
-detailed call sequences during startup.
-
-This uses the `systemd-bootchart` package, which is installed by default on
-VyOS 1.3 (equuleus) and later. Configuration is versioned for comparable
-results. Refer to [bootchart.conf] for the configuration file.
-
-To enable boot time graphing, add the following to the kernel command line:
-`init=/usr/lib/systemd/systemd-bootchart`
-
-You can also make this permanent by editing `/boot/grub/grub.cfg`.
-
-## Priorities
-
-VyOS CLI depends heavily on priorities. Every CLI node has a corresponding
-`node.def` file and possibly an attached script. Nodes can have priorities,
-and on system bootup or any `commit` to the configuration, scripts execute
-from lowest to highest priority. This provides deterministic behavior.
-
-To debug priority issues or see script execution order, use the
-`/opt/vyatta/sbin/priority.pl` script, which lists the execution order of
-scripts.
-
-[bootchart.conf]: https://github.com/vyos/vyos-build/blob/current/data/live-build-config/includes.chroot/etc/systemd/bootchart.conf
-[vyatta-cfg]: https://github.com/vyos/vyatta-cfg