Merge remote-tracking branch 'origin/master' into worktree/chat-ui-polish

# Conflicts:
#	packages/client/ui-conversation/README.i18n.yaml
#	packages/client/ui-conversation/src/client/chat/MessageItem.tsx
#	packages/client/ui-conversation/tests/chat-branch-tails.spec.tsx

packages/client/ui-conversation/tests/chat-branch-tails.spec.tsx

@@ -107,15 +107,48 @@ describe('MessageItem arms', () => {
     expect(view.queryByRole('button', { name: '复制' })).toBeNull()
   })
 
-  it('context and unknown nodes render their JSON rows', () => {
+  it('context uses the Tool calls disclosure chrome and keeps its JSON collapsed by default', () => {
     const ctxView = render(
-      <MessageItem node={{ kind: 'context', seq: 3, content: [], source: null } as never} />,
+      <MessageItem node={{
+        kind: 'context',
+        seq: 3,
+        content: [{ type: 'text', text: 'x\n"y":,[{}]' }],
+        source: { kind: 'plugin', plugin: 'fixture', empty: {}, list: [] },
+      } as never}
+      />,
     )
-    const contextToggle = ctxView.getByRole('button', { name: '上下文注入' })
-    expect(contextToggle.getAttribute('aria-expanded')).toBe('false')
-    expect(contextToggle.querySelector('svg')).not.toBeNull()
-    fireEvent.click(contextToggle)
-    expect(contextToggle.getAttribute('aria-expanded')).toBe('true')
+    const disclosure = ctxView.getByRole('button', { name: '上下文注入' })
+    expect(disclosure.getAttribute('aria-expanded')).toBe('false')
+    expect(ctxView.container.querySelector('[data-context-injection-body]')).toBeNull()
+    expect(ctxView.container.querySelector('svg')).not.toBeNull()
+
+    fireEvent.click(disclosure)
+    expect(disclosure.getAttribute('aria-expanded')).toBe('true')
+    expect(ctxView.container.querySelector('[data-context-injection-body]')?.textContent).toBe(
+      '{ "content": [ { "type": "text", "text": "x\\n\\"y\\":,[{}]" } ], '
+      + '"source": { "kind": "plugin", "plugin": "fixture", "empty": {}, "list": [] } }',
+    )
+
+    fireEvent.keyDown(disclosure, { key: ' ' })
+    expect(disclosure.getAttribute('aria-expanded')).toBe('false')
+  })
+
+  it('context preserves the bounded JSON truncation contract', () => {
+    const view = render(
+      <MessageItem node={{
+        kind: 'context',
+        seq: 3,
+        content: [{ type: 'text', text: 'x'.repeat(21_000) }],
+        source: null,
+      } as never}
+      />,
+    )
+    fireEvent.click(view.getByRole('button', { name: '上下文注入' }))
+    expect(view.container.querySelector('[data-context-injection-body]')?.textContent)
+      .toMatch(/… 已截断，共 \d+ 字符$/)
+  })
+
+  it('unknown nodes retain the generic JSON row', () => {
     const unknownView = render(
       <MessageItem node={{ kind: 'unknown', seq: 4, type: 'surface/next', data: { x: 1 } } as never} />,
     )