feat(tui): read display.streaming / show_reasoning / show_cost / inline_diffs from config

Extends ConfigDisplayConfig and UiState so the four new display flags
flow from `config.get {key:"full"}` into the nanostore. applyDisplay is
exported to keep the fan-out testable without an Ink harness.

Defaults mirror v1 parity: streaming + inline_diffs default true
(opt-out via `=== false`), show_cost + show_reasoning default false
(opt-in via plain truthy check).

ui-tui/src/__tests__/useConfigSync.test.ts

@@ -0,0 +1,67 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { $uiState, resetUiState } from '../app/uiStore.js'
+import { applyDisplay } from '../app/useConfigSync.js'
+
+describe('applyDisplay', () => {
+  beforeEach(() => {
+    resetUiState()
+  })
+
+  it('fans every display flag out to $uiState and the bell callback', () => {
+    const setBell = vi.fn()
+
+    applyDisplay(
+      {
+        config: {
+          display: {
+            bell_on_complete: true,
+            details_mode: 'expanded',
+            inline_diffs: false,
+            show_cost: true,
+            show_reasoning: true,
+            streaming: false,
+            tui_compact: true,
+            tui_statusbar: false
+          }
+        }
+      },
+      setBell
+    )
+
+    const s = $uiState.get()
+    expect(setBell).toHaveBeenCalledWith(true)
+    expect(s.compact).toBe(true)
+    expect(s.detailsMode).toBe('expanded')
+    expect(s.inlineDiffs).toBe(false)
+    expect(s.showCost).toBe(true)
+    expect(s.showReasoning).toBe(true)
+    expect(s.statusBar).toBe(false)
+    expect(s.streaming).toBe(false)
+  })
+
+  it('applies v1 parity defaults when display fields are missing', () => {
+    const setBell = vi.fn()
+
+    applyDisplay({ config: { display: {} } }, setBell)
+
+    const s = $uiState.get()
+    expect(setBell).toHaveBeenCalledWith(false)
+    expect(s.inlineDiffs).toBe(true)
+    expect(s.showCost).toBe(false)
+    expect(s.showReasoning).toBe(false)
+    expect(s.statusBar).toBe(true)
+    expect(s.streaming).toBe(true)
+  })
+
+  it('treats a null config like an empty display block', () => {
+    const setBell = vi.fn()
+
+    applyDisplay(null, setBell)
+
+    const s = $uiState.get()
+    expect(setBell).toHaveBeenCalledWith(false)
+    expect(s.inlineDiffs).toBe(true)
+    expect(s.streaming).toBe(true)
+  })
+})

ui-tui/src/app/interfaces.ts

@@ -78,9 +78,13 @@ export interface UiState {
   compact: boolean
   detailsMode: DetailsMode
   info: null | SessionInfo
+  inlineDiffs: boolean
+  showCost: boolean
+  showReasoning: boolean
   sid: null | string
   status: string
   statusBar: boolean
+  streaming: boolean
   theme: Theme
   usage: Usage
 }

ui-tui/src/app/uiStore.ts

@@ -11,9 +11,13 @@ const buildUiState = (): UiState => ({
   compact: false,
   detailsMode: 'collapsed',
   info: null,
+  inlineDiffs: true,
+  showCost: false,
+  showReasoning: false,
   sid: null,
   status: 'summoning hermes…',
   statusBar: true,
+  streaming: true,
   theme: DEFAULT_THEME,
   usage: ZERO
 })

ui-tui/src/app/useConfigSync.ts

@@ -27,14 +27,18 @@ const quietRpc = async <T extends Record<string, any> = Record<string, any>>(
   }
 }
 
-const applyDisplay = (cfg: ConfigFullResponse | null, setBell: (v: boolean) => void) => {
+export const applyDisplay = (cfg: ConfigFullResponse | null, setBell: (v: boolean) => void) => {
   const d = cfg?.config?.display ?? {}
 
   setBell(!!d.bell_on_complete)
   patchUiState({
     compact: !!d.tui_compact,
     detailsMode: resolveDetailsMode(d),
-    statusBar: d.tui_statusbar !== false
+    inlineDiffs: d.inline_diffs !== false,
+    showCost: !!d.show_cost,
+    showReasoning: !!d.show_reasoning,
+    statusBar: d.tui_statusbar !== false,
+    streaming: d.streaming !== false
   })
 }
 

ui-tui/src/gatewayTypes.ts

@@ -53,6 +53,10 @@ export type CommandDispatchResponse =
 export interface ConfigDisplayConfig {
   bell_on_complete?: boolean
   details_mode?: string
+  inline_diffs?: boolean
+  show_cost?: boolean
+  show_reasoning?: boolean
+  streaming?: boolean
   thinking_mode?: string
   tui_compact?: boolean
   tui_statusbar?: boolean