refactor(cli): remove OpenAI codex auth plugin setup

OpenCode now natively supports OpenAI authentication, so we no longer
need to:
- Add opencode-openai-codex-auth plugin
- Configure CODEX_PROVIDER_CONFIG provider settings

The --chatgpt flag still controls Oracle agent model selection
(GPT-5.2 vs fallback).

README.ja.md

@@ -91,8 +91,7 @@
       - [4.2 Google Gemini (Antigravity OAuth)](#42-google-gemini-antigravity-oauth)
       - [4.2.1 モデル設定](#421-モデル設定)
       - [4.2.2 oh-my-opencode エージェントモデルのオーバーライド](#422-oh-my-opencode-エージェントモデルのオーバーライド)
-      - [4.3 OpenAI (ChatGPT Plus/Pro)](#43-openai-chatgpt-pluspro)
-        - [モデル設定](#モデル設定)
+
     - [⚠️ 注意](#️-注意)
     - [セットアップの確認](#セットアップの確認)
     - [ユーザーに「おめでとうございます！🎉」と伝える](#ユーザーにおめでとうございますと伝える)

README.md

@@ -94,8 +94,7 @@
       - [Google Gemini (Antigravity OAuth)](#google-gemini-antigravity-oauth)
         - [Model Configuration](#model-configuration)
         - [oh-my-opencode Agent Model Override](#oh-my-opencode-agent-model-override)
-      - [OpenAI (ChatGPT Plus/Pro)](#openai-chatgpt-pluspro)
-        - [Model Configuration](#model-configuration-1)
+
     - [⚠️ Warning](#️-warning)
     - [Verify the setup](#verify-the-setup)
     - [Say 'Congratulations! 🎉' to the user](#say-congratulations--to-the-user)

README.zh-cn.md

@@ -93,8 +93,7 @@
       - [Google Gemini (Antigravity OAuth)](#google-gemini-antigravity-oauth)
         - [模型配置](#模型配置)
         - [oh-my-opencode 智能体模型覆盖](#oh-my-opencode-智能体模型覆盖)
-      - [OpenAI (ChatGPT Plus/Pro)](#openai-chatgpt-pluspro)
-        - [模型配置](#模型配置-1)
+
     - [⚠️ 警告](#️-警告)
     - [验证安装](#验证安装)
     - [向用户说 '恭喜！🎉'](#向用户说-恭喜)

src/cli/config-manager.ts

@@ -436,11 +436,7 @@ export async function addAuthPlugins(config: InstallConfig): Promise<ConfigMerge
       }
     }
 
-    if (config.hasChatGPT) {
-      if (!plugins.some((p) => p.startsWith("opencode-openai-codex-auth"))) {
-        plugins.push("opencode-openai-codex-auth")
-      }
-    }
+
 
     const newConfig = { ...(existingConfig ?? {}), plugin: plugins }
     writeFileSync(path, JSON.stringify(newConfig, null, 2) + "\n")
@@ -550,54 +546,7 @@ export const ANTIGRAVITY_PROVIDER_CONFIG = {
   },
 }
 
-const CODEX_PROVIDER_CONFIG = {
-  openai: {
-    name: "OpenAI",
-    options: {
-      reasoningEffort: "medium",
-      reasoningSummary: "auto",
-      textVerbosity: "medium",
-      include: ["reasoning.encrypted_content"],
-      store: false,
-    },
-    models: {
-      "gpt-5.2": {
-        name: "GPT 5.2 (OAuth)",
-        limit: { context: 272000, output: 128000 },
-        modalities: { input: ["text", "image"], output: ["text"] },
-        variants: {
-          none: { reasoningEffort: "none", reasoningSummary: "auto", textVerbosity: "medium" },
-          low: { reasoningEffort: "low", reasoningSummary: "auto", textVerbosity: "medium" },
-          medium: { reasoningEffort: "medium", reasoningSummary: "auto", textVerbosity: "medium" },
-          high: { reasoningEffort: "high", reasoningSummary: "detailed", textVerbosity: "medium" },
-          xhigh: { reasoningEffort: "xhigh", reasoningSummary: "detailed", textVerbosity: "medium" },
-        },
-      },
-      "gpt-5.2-codex": {
-        name: "GPT 5.2 Codex (OAuth)",
-        limit: { context: 272000, output: 128000 },
-        modalities: { input: ["text", "image"], output: ["text"] },
-        variants: {
-          low: { reasoningEffort: "low", reasoningSummary: "auto", textVerbosity: "medium" },
-          medium: { reasoningEffort: "medium", reasoningSummary: "auto", textVerbosity: "medium" },
-          high: { reasoningEffort: "high", reasoningSummary: "detailed", textVerbosity: "medium" },
-          xhigh: { reasoningEffort: "xhigh", reasoningSummary: "detailed", textVerbosity: "medium" },
-        },
-      },
-      "gpt-5.1-codex-max": {
-        name: "GPT 5.1 Codex Max (OAuth)",
-        limit: { context: 272000, output: 128000 },
-        modalities: { input: ["text", "image"], output: ["text"] },
-        variants: {
-          low: { reasoningEffort: "low", reasoningSummary: "detailed", textVerbosity: "medium" },
-          medium: { reasoningEffort: "medium", reasoningSummary: "detailed", textVerbosity: "medium" },
-          high: { reasoningEffort: "high", reasoningSummary: "detailed", textVerbosity: "medium" },
-          xhigh: { reasoningEffort: "xhigh", reasoningSummary: "detailed", textVerbosity: "medium" },
-        },
-      },
-    },
-  },
-}
+
 
 export function addProviderConfig(config: InstallConfig): ConfigMergeResult {
   try {
@@ -627,10 +576,6 @@ export function addProviderConfig(config: InstallConfig): ConfigMergeResult {
       providers.google = ANTIGRAVITY_PROVIDER_CONFIG.google
     }
 
-    if (config.hasChatGPT) {
-      providers.openai = CODEX_PROVIDER_CONFIG.openai
-    }
-
     if (Object.keys(providers).length > 0) {
       newConfig.provider = providers
     }
@@ -675,7 +620,6 @@ export function detectCurrentConfig(): DetectedConfig {
   }
 
   result.hasGemini = plugins.some((p) => p.startsWith("opencode-antigravity-auth"))
-  result.hasChatGPT = plugins.some((p) => p.startsWith("opencode-openai-codex-auth"))
 
   const omoConfigPath = getOmoConfig()
   if (!existsSync(omoConfigPath)) {

src/cli/install.ts

@@ -281,7 +281,7 @@ async function runNonTuiInstall(args: InstallArgs): Promise<number> {
   }
   printSuccess(`Plugin ${isUpdate ? "verified" : "added"} ${SYMBOLS.arrow} ${color.dim(pluginResult.configPath)}`)
 
-  if (config.hasGemini || config.hasChatGPT) {
+  if (config.hasGemini) {
     printStep(step++, totalSteps, "Adding auth plugins...")
     const authResult = await addAuthPlugins(config)
     if (!authResult.success) {
@@ -392,7 +392,7 @@ export async function install(args: InstallArgs): Promise<number> {
   }
   s.stop(`Plugin added to ${color.cyan(pluginResult.configPath)}`)
 
-  if (config.hasGemini || config.hasChatGPT) {
+  if (config.hasGemini) {
     s.start("Adding auth plugins (fetching latest versions)")
     const authResult = await addAuthPlugins(config)
     if (!authResult.success) {