Merge remote-tracking branch 'origin/master' into worktree/web-multimodal-image-input

# Conflicts:
#	packages/client/runtime/README.i18n.yaml
#	packages/client/ui-conversation/README.i18n.yaml
#	packages/client/ui-conversation/README.md
#	packages/client/ui-conversation/README.zh.md
#	packages/client/ui-conversation/src/client/chat/MessageItem.tsx

packages/client/test-runtime/README.i18n.yaml

@@ -2,5 +2,5 @@
 # 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 packages/client/test-runtime/README.md
-README.md: 883d71224139dc409229fdfb35362d040e810cc7
-README.zh.md: a3daf112940b03b585d44bc5fd1317e43ebd35fe
+README.md: dc8ee8cadf5e61af15f04b1b9842af1eb658c031
+README.zh.md: a4c889d8a0291b52c8509403748df6b93567788e

packages/client/test-runtime/README.md

@@ -21,4 +21,4 @@ None; this package neither assembles nor sends a provider request.
 ## Known Limitations and Deferred Work
 
 - **Consumed through repository source aliases only.** Specs resolve the package through tsconfig `paths` to `src`; the built `lib/` artifact re-exports `@deepseek-ai/dsh-client-runtime/client`, whose bundle is a browser loader script with no Node ESM exports, so `lib/index.js` is not importable under plain Node. Acceptable while every consumer is an in-repo Vitest suite; a Node-compatible runtime entry is deferred until an out-of-repo consumer exists.
-- **Conversation snapshots are fixture data, not replayed history.** `updateSnapshot` writes the snapshot store directly; the wire-to-snapshot computation stays covered by the runtime package's own tests and the replay e2e. A fixture can therefore express states the production fold would never produce.
+- **Conversation snapshots are fixture data, not replayed history.** `updateSnapshot` writes the snapshot store directly; the wire-to-snapshot computation stays covered by the runtime package's own tests and the replay e2e. A fixture can therefore express states the production projection would never produce.

packages/client/test-runtime/README.zh.md

@@ -21,4 +21,4 @@
 ## Known Limitations and Deferred Work
 
 - **仅可经仓内源码别名消费。** spec 通过 tsconfig `paths` 解析到 `src`；构建产物 `lib/` 再导出 `@deepseek-ai/dsh-client-runtime/client`，而该 bundle 是无 Node ESM 导出的浏览器 loader 脚本，故 `lib/index.js` 在纯 Node 下不可导入。当前所有消费方都是仓内 Vitest 套件，可接受；Node 兼容的运行时入口待出现仓外消费方再补。
-- **会话快照是 fixture 数据，不是重放历史。** `updateSnapshot` 直写快照 store；wire 到快照的运算仍由 runtime 包自身测试与 replay e2e 把守。因此 fixture 可以表达生产折叠永不产出的状态。
+- **会话快照是 fixture 数据，不是重放历史。** `updateSnapshot` 直写快照 store；wire 到快照的运算仍由 runtime 包自身测试与 replay e2e 把守。因此 fixture 可以表达生产投影永不产出的状态。

packages/client/test-runtime/src/fixtures.ts

@@ -46,7 +46,6 @@ export function conversationSnapshot(sessionId: SessionId): ConversationSnapshot
   return {
     sessionId,
     nodes: [],
-    foldDegraded: false,
     partial: null,
     runningCalls: [],
     codeDispatches: new Map(),

packages/client/test-runtime/src/index.ts

@@ -38,6 +38,7 @@ export { TestWorkspaces } from './workspaces.ts'
 export { conversationSnapshot, workspaceListState } from './fixtures.ts'
 export type { SessionBehaviorOverrides, SessionFixture, Stabilizer } from './fixtures.ts'
 export { makeTranslate } from './translate.ts'
+export { usePinnedBrowserLanguages } from './locale-env.ts'
 
 /** Erased register face for the internal root call (the public declare seam holds the typing). */
 type ErasedRegister = (options: object, component: unknown) => () => void

packages/client/test-runtime/src/locale-env.ts

@@ -0,0 +1,29 @@
+/**
+ * Browser-language pin for specs that assert localized copy. A fresh
+ * LocaleService with no stored preference opens in the language `navigator`
+ * asks for, and jsdom reports the runner's own (`en-US`) — so a spec asserting
+ * the product's Chinese copy states the browser it assumes instead of
+ * inheriting the machine's.
+ */
+import { afterEach, beforeEach } from 'vitest'
+
+/**
+ * Pin `navigator.languages`/`navigator.language` for every test in the
+ * calling file (or describe block), restoring the environment's own values
+ * afterwards. Call at suite level, like the other vitest hooks.
+ * @param primary - most preferred BCP 47 tag; also becomes `navigator.language`.
+ * @param rest - further tags in preference order.
+ */
+export function usePinnedBrowserLanguages(primary: string, ...rest: string[]): void {
+  beforeEach(() => {
+    Object.defineProperty(navigator, 'languages', { value: [primary, ...rest], configurable: true })
+    Object.defineProperty(navigator, 'language', { value: primary, configurable: true })
+  })
+  afterEach(() => {
+    // Deleting the own properties uncovers the environment's own accessors
+    // again (Navigator declares both readonly, hence the erased receiver).
+    const own = navigator as unknown as Record<string, unknown>
+    delete own.languages
+    delete own.language
+  })
+}