docs(claude.md): document LLM-facing files and RTD layout

Add two sections to CLAUDE.md so future contributors (and AI coding
agents) know where llms.txt comes from and how html_baseurl per branch
should be set:

- LLM-Facing Files: how llms.txt is rendered from the Jinja template at
  build time, where the hook lives, and the rule for adding new
  top-level sections.
- Read the Docs Layout: canonical version slugs (rolling/1.5/1.4/...)
  vs URL-level redirect aliases (latest/lts/stable/codename), with the
  rule that html_baseurl points at the canonical not the alias.

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

1 files changed, 39 insertions, 0 deletions

diff --git a/CLAUDE.md b/CLAUDE.md
index 60f7d13f..4785e8bc 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -105,6 +105,45 @@ Each configuration page should contain:
 4. **Known issues** — problems and workarounds
 5. **Debugging** — log collection, `show` commands, state indicators
 
+## LLM-Facing Files (`llms.txt`, `llms-full.txt`)
+
+Both files are regenerated on every Sphinx HTML build. They're shipped at the
+docs root for each version (`https://docs.vyos.io/en/<version>/llms.txt`,
+`.../llms-full.txt`).
+
+- **`llms-full.txt`** — auto-generated by the `sphinx_llms_txt` extension from
+  the full corpus. No curation; configured by `llms_txt_file = False` (which
+  disables the extension's *index* output, not the full output).
+- **`llms.txt`** — curated overview rendered at build time from
+  `docs/_templates/llms.txt.j2`. URLs and the version line are interpolated
+  from `html_baseurl` and `release` so the file always matches the branch.
+  The render lives in `_write_llms_txt(app, exception)` in `docs/conf.py`,
+  wired via `app.connect('build-finished', ...)`.
+
+When adding new top-level sections to the docs, add a corresponding bullet in
+`docs/_templates/llms.txt.j2`. Branch-specific differences (e.g. sagitta has
+no `vpp/` or `contributing/index`) live in that branch's copy of the template.
+
+## Read the Docs Layout
+
+RTD slugs as of 2026-05-04 (verified via API):
+
+| Slug | Verbose | Branch | Role |
+|---|---|---|---|
+| `rolling` | current | `current` | canonical for rolling/next major |
+| `1.5` | circinus | `circinus` | canonical for current LTS |
+| `1.4` | sagitta | `sagitta` | canonical for previous LTS |
+| `1.3`, `1.2` | equuleus, crux | older | canonical for older releases |
+
+URL-level redirect aliases (resolve to the canonicals above):
+`/en/latest/* → /en/rolling/`, `/en/lts/* → /en/1.5/`,
+`/en/stable/* → /en/lts/`, `/en/circinus*`, `/en/sagitta*`,
+`/en/equuleus*`, `/en/crux*` → numeric slugs.
+
+`html_baseurl` per branch must point at the canonical (numeric or `rolling`),
+not the alias, so `<link rel="canonical">` and the sitemap match what RTD
+serves and crawlers skip the redirect hop.
+
 ## CI
 
 - **Linter** (`doc-linter.py` from `vyos/.github`): checks line length and IP addresses on changed files only