fix(user-interaction): preserve multi-select custom answers

packages/ui/user-interaction/README.i18n.yaml

@@ -1,6 +1,6 @@
 # Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
-#   pnpm run verify-translation-pairing --write
-README.md: d234d6677bdd772f1bbd2c979c0d41f90aef5c32
-README.zh.md: b70a61d6491e0bb0e52215cdeaeea3d728f7f153
+#   pnpm run verify-translation-pairing --write packages/ui/user-interaction/README.md
+README.md: 2ff29f5fd6244ebcf7e29b86f5de1cde30944532
+README.zh.md: 7d0d1b06db5be4353e42d1905c71d5dff963b97d

packages/ui/user-interaction/README.md

@@ -19,7 +19,7 @@ Abstract user-interaction seam. It owns `ctx.userInteraction`, the service a mod
 - `UserInteractionProvider` — UI implementation with `ask(request)`.
 - `UserInteractionError` — `HarnessError` subclass with codes such as `EMPTY_QUESTIONS`, `NO_PROVIDER`, `DUPLICATE_PROVIDER`, and `ASK_ABORTED`.
 
-When an answer includes `custom`, `selected` is empty; custom text is an override rather than a supplement to selected choices. A UI may preserve a skipped item as `{ id, selected: [] }`, keeping the existing answer shape while retaining other answers in the batch.
+For a single-select question, `custom` overrides the selected choice and `selected` is empty. For a multi-select question, `custom` may supplement the labels in `selected`. A UI may preserve a skipped item as `{ id, selected: [] }`, keeping the existing answer shape while retaining other answers in the batch.
 
 ## Role
 

packages/ui/user-interaction/README.zh.md

@@ -19,7 +19,7 @@
 - `UserInteractionProvider`：包含 `ask(request)` 的 UI 实现。
 - `UserInteractionError`：`HarnessError` 的子类，包含 `EMPTY_QUESTIONS`、`NO_PROVIDER`、`DUPLICATE_PROVIDER` 和 `ASK_ABORTED` 等代码。
 
-当回答包含 `custom` 时，`selected` 为空；自定义文本会覆盖所选选项，而不是补充它们。UI 可以把跳过的条目保留为 `{ id, selected: [] }`，既维持现有回答形态，也保留该批次中的其他回答。
+对于单选题，`custom` 会覆盖选中的选项，且 `selected` 为空。对于多选题，`custom` 可以补充 `selected` 中的标签。UI 可以把跳过的条目保留为 `{ id, selected: [] }`，既维持现有回答形态，也保留该批次中的其他回答。
 
 ## 职责
 

packages/ui/user-interaction/src/types.ts

@@ -33,7 +33,7 @@ export interface AskUserQuestionItem {
 export interface AskUserQuestionAnswerItem {
   /** The answered question id. */
   id: string
-  /** Selected option labels. Empty for custom or unanswered choices. */
+  /** Selected option labels. May accompany custom text for a multi-select question. */
   selected: string[]
   /** Optional free-text "Other" answer. */
   custom?: string