Added
- Plugins can read recent chat history via a new
ctx.engine.getChatHistory(sessionId, chatId, limit?, includeMedia?)capability, gated by theengine:readpermission and the plugin's active-session scope like the other engine reads. The limit is clamped host-side (max 100), and both message directions are returned. This is the host-side prerequisite for an adapter to backfill prior conversation context. (#609)