Fix startup effort alias default display

Preserve provider alias reasoning defaults in the startup banner when no saved /effort value or CLAUDE_CODE_EFFORT_LEVEL override is present. Saved settings and env overrides still take precedence, and xhigh aliases are normalized through the standard effort representation before display.

Add a regression test for the gpt-5.4 OpenAI banner showing the alias default high effort in a clean settings session.

Author: jatmn

src/components/StartupScreen.test.ts

@@ -269,6 +269,14 @@ describe('detectProvider — explicit dedicated-provider env flags', () => {
 })
 
 describe('detectProvider — startup effort display', () => {
+  test('OpenAI startup banner uses provider alias default when no saved or env effort is set', () => {
+    setupOpenAIMode('https://api.openai.com/v1', 'gpt-5.4')
+
+    const result = detectProvider()
+
+    expect(result.model).toBe('gpt-5.4 (high)')
+  })
+
   test('OpenAI startup banner uses saved /effort over provider alias default', () => {
     setupOpenAIMode('https://api.openai.com/v1', 'gpt-5.4')
     setSessionSettingsCache({ settings: { effortLevel: 'medium' }, errors: [] })

src/components/StartupScreen.ts

@@ -17,8 +17,10 @@ import { DEFAULT_GEMINI_MODEL } from '../utils/providerProfile.js'
 import { getGlobalConfig } from '../utils/config.js'
 import {
   getDisplayedEffortLevel,
+  getEffortEnvOverride,
   getInitialEffortSetting,
   modelSupportsEffort,
+  openAIEffortToStandard,
 } from '../utils/effort.js'
 import { ANSI_DIM, ANSI_RESET, ansiRgb } from '../utils/terminalAnsi.js'
 import {
@@ -156,7 +158,14 @@ export function detectProvider(modelOverride?: string): { name: string; model: s
     // provider alias may carry a default reasoning effort, but saved /effort
     // and CLAUDE_CODE_EFFORT_LEVEL must take precedence in the startup banner.
     if (modelSupportsEffort(displayModel)) {
-      displayModel = `${displayModel} (${getDisplayedEffortLevel(displayModel, getInitialEffortSetting())})`
+      const savedEffort = getInitialEffortSetting()
+      const aliasDefaultEffort =
+        getEffortEnvOverride() === undefined &&
+        savedEffort === undefined &&
+        resolvedRequest.reasoning?.effort
+          ? openAIEffortToStandard(resolvedRequest.reasoning.effort)
+          : undefined
+      displayModel = `${displayModel} (${getDisplayedEffortLevel(displayModel, savedEffort ?? aliasDefaultEffort)})`
     }
 
     return { name, model: displayModel, baseUrl, isLocal }