fix(native-chat): render Claude structured chat through the same UI as Codex

Structured native chat is one shared, agent-agnostic component tree, but three
Codex-hardcoded terms on that path made a Claude session render differently.

- `showTurnStatus` was `agent === 'codex'`, which gated the whole structured
  presentation: the live tool-progress row, the completion check and activity
  grouping (`structuredActivityUi`), and the Thinking / Working for N /
  Worked for N status rows. Claude fell back to the legacy compact chrome.
- `runtimeContext` was likewise Codex-only, so a Claude transcript rendered
  images as filename chips instead of previews.
- The composer's structured slash menu always served the Codex catalog,
  ignoring `agent`. That disagreed with the dispatcher, which does branch per
  agent: Codex-only tokens offered to Claude missed the command guard and were
  sent to the model as literal prompt text, where Codex shows an error.

The first two gates landed Codex-first (#17597, #18266) before the Claude
structured lane existed; they were rollout scoping, not capability limits.
Neither `useNativeChatTurnStatus` nor `useNativeChatImageRuntimeContext` has
any agent-specific logic. The menu now reads `structuredSlashCommands(agent)`,
the function the dispatcher already used, so both read one list.

No new rendering logic: two gates removed and one existing shared function
reused. There are now zero `agent === 'codex' | 'claude'` branches in any
native-chat component.

src/renderer/src/components/native-chat/NativeChatComposer.test.tsx

@@ -6,7 +6,6 @@ import type {
   SessionOptionDescriptor,
   SessionOptionsSurface
 } from '../../../../shared/native-chat-session-options'
-import type * as nativeChatAgentProfiles from '../../../../shared/native-chat-agent-profiles'
 import { clearNativeChatSessionOptionCacheForTests } from './native-chat-session-option-cache'
 import { clearNativeChatModelEnrichmentForTests } from './native-chat-session-option-enrichment'
 
@@ -27,6 +26,7 @@ const mocks = vi.hoisted(() => ({
     sessionOptionsSnapshot?: SessionOptionDescriptor[]
     attachDisabled?: boolean
     sendButtonDisabled?: boolean
+    autocomplete?: { mode: string; items?: { kind: string; name: string }[] }
   } | null,
   modelSwitchOutcome: 'applied' as 'applied' | 'rejected' | 'unknown',
   confirmationObserver: null as {
@@ -90,10 +90,6 @@ vi.mock('./claude-model-switch-confirmation', () => ({
   createClaudeModelSwitchConfirmationObserver: (...args: unknown[]) =>
     mocks.createClaudeModelSwitchConfirmationObserver(...args)
 }))
-vi.mock('../../../../shared/native-chat-agent-profiles', async (importOriginal) => ({
-  ...(await importOriginal<typeof nativeChatAgentProfiles>()),
-  getVerifiedNativeChatCommands: () => []
-}))
 vi.mock('@/lib/native-chat-telemetry', () => ({
   emitNativeChatMessageSent: vi.fn(),
   emitNativeChatPickerItemAccepted: vi.fn(),
@@ -308,6 +304,43 @@ describe('NativeChatComposer', () => {
     expect(mocks.setDraft).toHaveBeenCalledWith('')
   })
 
+  // The structured slash menu must offer the running agent's own catalog. Offering
+  // another agent's tokens sends them past the command guard as literal prompt text.
+  it.each([
+    ['claude', 'compact', 'vim'],
+    ['codex', 'vim', 'help']
+  ] as const)('offers %s its own structured slash commands', (agent, offered, withheld) => {
+    mocks.draft = '/'
+    render(
+      <NativeChatComposer
+        terminalTabId="tab-1"
+        paneKey={`tab-1:structured-${agent}`}
+        targetPtyId={null}
+        agent={agent}
+        structuredTransport={{
+          send: vi.fn(() => true),
+          dispatchCommand: vi.fn(async () => ({ handled: false, accepted: false, error: null })),
+          optionsSurface: {
+            getSnapshot: () => [],
+            setOption: vi.fn(),
+            invokeAction: vi.fn(),
+            subscribe: () => () => {}
+          },
+          optionSnapshot: [],
+          onError: vi.fn(),
+          runtime: 'local'
+        }}
+      />
+    )
+
+    const names = (mocks.fieldProps?.autocomplete?.items ?? [])
+      .filter((item) => item.kind === 'command')
+      .map((item) => item.name)
+    expect(names).toContain(offered)
+    expect(names).toContain('effort')
+    expect(names).not.toContain(withheld)
+  })
+
   it('sends structured image attachments through the durable transport', async () => {
     mocks.draft = ''
     mocks.imageAttachments = [{ id: 'image-1', path: '/tmp/image.png' }]

src/renderer/src/components/native-chat/NativeChatComposer.tsx

@@ -3,7 +3,7 @@ import { useAppStore } from '../../store'
 import { sendRuntimePtyInput } from '@/runtime/runtime-terminal-inspection'
 import { getSettingsForAgentTabRuntimeOwner } from '@/lib/agent-paste-draft'
 import { getVerifiedNativeChatCommands } from '../../../../shared/native-chat-agent-profiles'
-import { STRUCTURED_AGENT_SESSION_SLASH_COMMANDS } from '../../../../shared/structured-agent-session-composer'
+import { structuredSlashCommands } from '../../../../shared/structured-agent-session-composer'
 import {
   applyMentionSuggestion,
   EMPTY_HISTORY,
@@ -111,9 +111,7 @@ const NativeChatComposerPane = forwardRef<NativeChatComposerHandle, NativeChatCo
 
     const agentCommands = useMemo(
       () =>
-        structuredTransport
-          ? STRUCTURED_AGENT_SESSION_SLASH_COMMANDS
-          : getVerifiedNativeChatCommands(agent),
+        structuredTransport ? structuredSlashCommands(agent) : getVerifiedNativeChatCommands(agent),
       [agent, structuredTransport]
     )
     const picker = useNativeChatPickerState({

src/renderer/src/components/native-chat/NativeChatStructuredSession.test.tsx

@@ -14,6 +14,8 @@ const mocks = vi.hoisted(() => ({
   messageListProps: null as null | {
     allowFileUriLinks?: boolean
     onLinkClick?: (...args: unknown[]) => void
+    showTurnStatus?: boolean
+    runtimeContext?: unknown
   },
   composerProps: null as null | { structuredTransport?: Record<string, unknown> },
   questionCardProps: null as NativeChatQuestionCardProps | null,
@@ -190,6 +192,27 @@ describe('NativeChatStructuredSession', () => {
     expect(mocks.messageListProps?.onLinkClick).toBe(mocks.fileLinkClick)
   })
 
+  // Turn status and transcript image previews shipped Codex-first. Every
+  // structured session renders through the same list, so neither is agent-gated.
+  it.each(['codex', 'claude'] as const)(
+    'renders the same structured transcript chrome for %s',
+    (agent) => {
+      render(
+        <NativeChatStructuredSession
+          isVisible
+          tabId="structured-tab-parity"
+          sessionId="session-parity"
+          target={{ kind: 'local' }}
+          agent={agent}
+          allowFileUriLinks
+        />
+      )
+
+      expect(mocks.messageListProps?.showTurnStatus).toBe(true)
+      expect(mocks.messageListProps?.runtimeContext).not.toBeUndefined()
+    }
+  )
+
   it('routes a bare model command to the native option picker', async () => {
     render(
       <NativeChatStructuredSession

src/renderer/src/components/native-chat/NativeChatStructuredSession.tsx

@@ -166,10 +166,10 @@ export function NativeChatStructuredSession(
             expandSignal={false}
             fontScale={fontScale.scale}
             workingStartedAt={null}
-            showTurnStatus={props.agent === 'codex'}
+            showTurnStatus
             onLinkClick={fileLinkClick}
             allowFileUriLinks={fileLinkClick !== undefined}
-            runtimeContext={props.agent === 'codex' ? imageRuntimeContext : undefined}
+            runtimeContext={imageRuntimeContext}
           />
         )}
       </div>

src/shared/structured-agent-session-composer.test.ts

@@ -0,0 +1,31 @@
+import { describe, expect, it } from 'vitest'
+import {
+  isStructuredAgentSessionComposerCommand,
+  structuredSlashCommands
+} from './structured-agent-session-composer'
+
+describe('structuredSlashCommands', () => {
+  // The composer menu and the dispatcher read this one list. When they disagreed,
+  // a Claude session was offered Codex-only tokens that missed the command guard
+  // and reached the model as literal prompt text instead of erroring.
+  it.each(['codex', 'claude'] as const)('offers %s only commands it also accepts', (agent) => {
+    const offered = structuredSlashCommands(agent)
+    expect(offered.length).toBeGreaterThan(0)
+    for (const command of offered) {
+      expect(isStructuredAgentSessionComposerCommand(`/${command.name}`, agent)).toBe(true)
+    }
+  })
+
+  it('offers each agent its own catalog', () => {
+    const claude = structuredSlashCommands('claude').map((command) => command.name)
+    expect(claude).toContain('compact')
+    expect(claude).not.toContain('vim')
+    expect(structuredSlashCommands('codex').map((command) => command.name)).toContain('vim')
+  })
+
+  it('offers effort to every structured agent', () => {
+    for (const agent of ['codex', 'claude'] as const) {
+      expect(structuredSlashCommands(agent).map((command) => command.name)).toContain('effort')
+    }
+  })
+})

src/shared/structured-agent-session-composer.ts

@@ -35,7 +35,10 @@ function commandParts(text: string): { name: string; argument: string } | null {
   return match ? { name: match[1]!.toLowerCase(), argument: match[2]?.trim() ?? '' } : null
 }
 
-function structuredSlashCommands(agent: AgentType): readonly SlashCommandSuggestion[] {
+/** The command catalog a structured session offers and accepts. The composer menu
+ *  and the dispatcher must read the same list, or a menu pick falls through the
+ *  command guard and reaches the model as literal prompt text. */
+export function structuredSlashCommands(agent: AgentType): readonly SlashCommandSuggestion[] {
   if (agent === 'codex') {
     return STRUCTURED_AGENT_SESSION_SLASH_COMMANDS
   }