docs: describe the bundled renderer service

AGENTS.md

@@ -12,6 +12,11 @@ port of `tiennm99/mttools/monkeyd-crawler` under
 `internal/modules/monkeyd/{crawler,pdf,export}`. Change them here; they no
 longer track the mttools copy.
 
+`renderer/` is a separate Node 24 service (JavaScript + JSDoc, Remotion) that
+draws the `random` module's animations. It has its own `package.json`, tests,
+and `renderer/AGENTS.md`; run its npm commands from that folder. `compose.yml`
+deploys it next to the bot.
+
 ## Development Rules
 
 - Keep changes scoped to the requested module or shared contract.