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, 27 insertions, 0 deletions

diff --git a/docs/configuration/system/proxy.md b/docs/configuration/system/proxy.md
new file mode 100644
index 00000000..3b12634b
--- /dev/null
+++ b/docs/configuration/system/proxy.md
@@ -0,0 +1,27 @@
+(system-proxy)=
+
+# System Proxy
+
+Some IT environments require the use of a proxy to connect to the Internet.
+Without this configuration VyOS updates could not be installed directly by
+using the {opcmd}`add system image` command ({ref}`update_vyos`).
+
+```{cfgcmd} set system proxy url \<url\>
+
+Set proxy for all connections initiated by VyOS, including HTTP, HTTPS, and
+FTP (anonymous ftp).
+```
+```{cfgcmd} set system proxy port \<port\>
+
+Configure proxy port if it does not listen to the default port 80.
+```
+```{cfgcmd} set system proxy username \<username\>
+
+Some proxies require/support the "basic" HTTP authentication scheme as per
+{rfc}`7617`, thus a username can be configured.
+```
+```{cfgcmd} set system proxy password \<password\>
+
+Some proxies require/support the "basic" HTTP authentication scheme as per
+{rfc}`7617`, thus a password can be configured.
+```
\ No newline at end of file