refactor: consolidate duplicated Promise.all dual reads into resolveMessageContext utility

src/features/hook-message-injector/index.ts

@@ -4,6 +4,7 @@ export {
   findFirstMessageWithAgent,
   findNearestMessageWithFieldsFromSDK,
   findFirstMessageWithAgentFromSDK,
+  resolveMessageContext,
 } from "./injector"
 export type { StoredMessage } from "./injector"
 export type { MessageMeta, OriginalMessageContext, TextPart, ToolPermission } from "./types"