v0.8.7

Added

• Plugins can canonicalize a chat id via a new ctx.engine.canonicalChatId(sessionId, chatId) capability, gated by the engine:read permission like the other engine reads. It resolves a @lid privacy id to its stable <phone>@c.us form when the mapping is known (best-effort; an unresolved id passes through), letting a plugin key a chat by one identity across WhatsApp's @lid migration. This is the host-side prerequisite for an adapter to keep a contact's conversation from splitting when they migrate to @lid. (#615)