docs: translate remaining non-README documentation

docs/core-data-structures/goal.md

@@ -1,5 +1,7 @@
 # Same-session goals
 
+English | [中文](goal.zh.md)
+
 Types shared by the event-sourced goal domain and its policy consumers. The [goal-domain Agent Note](../../.agents/notes/implemented/feature/2026-07-19-persisted-same-session-goal-domain.md) owns the persistence and activation decisions; this page records the literal shapes from [`packages/goal/goal/src/types.ts`](../../packages/goal/goal/src/types.ts).
 
 ## Identity and lifecycle