docs: add docs.chatto.run (self-hosting) as doc reference alongside dev-docs

Separates the two Chatto doc sites by job: docs.chatto.run answers
server deployment/operation questions, dev-docs.chatto.run the API/
permissions/bot-behaviour ones.

AGENTS.md

@@ -21,6 +21,13 @@ is unclear on our side, the Chatto server source is the reference:
 git clone https://github.com/chattocorp/chatto.git
 ```
 
+Doc references, distinct jobs — know which one answers your question:
+
+- **https://docs.chatto.run/** — Chatto **self-hosting** documentation
+  (deploying and operating a Chatto server).
+- **https://dev-docs.chatto.run/** — Chatto **developer** documentation
+  (API, permissions, bot behaviour; e.g. the bots-cannot-start-DMs rule).
+
 The same repo's web frontend (`apps/frontend`) doubles as the architecture
 reference for client-side concerns — presence handling, caches, realtime
 consumption — because the bot is a Chatto client just like the browser. Read