Add changelog for new @trigger.dev/ai package

Co-authored-by: Eric Allam <eric@trigger.dev>

Author: cursoragent

packages/ai/CHANGELOG.md

@@ -0,0 +1,10 @@
+# @trigger.dev/ai
+
+## 4.3.3
+
+### Added
+
+- Introduced a new `@trigger.dev/ai` package.
+- Added `ai.tool(...)` and `ai.currentToolOptions()` helpers for AI SDK tool ergonomics.
+- Added `TriggerChatTransport` / `createTriggerChatTransport(...)` for AI SDK `useChat()` integrations powered by Trigger.dev tasks and Realtime Streams v2.
+- Added rich default chat payload typing (`chatId`, `trigger`, `messageId`, `messages`, request context) and mapper hooks for custom payloads.