feat(coding-agent): Add widget placement option (#850)

* Add widget placement for extension widgets

* Remove changelog entry for widget placement

* Keep no-op widget signature

* Move widget render before attach

packages/coding-agent/src/index.ts

@@ -66,6 +66,7 @@ export type {
 	ExtensionShortcut,
 	ExtensionUIContext,
 	ExtensionUIDialogOptions,
+	ExtensionWidgetOptions,
 	InputEvent,
 	InputEventResult,
 	InputSource,
@@ -94,6 +95,7 @@ export type {
 	TurnStartEvent,
 	UserBashEvent,
 	UserBashEventResult,
+	WidgetPlacement,
 } from "./core/extensions/index.js";
 export {
 	ExtensionRunner,