fix(openai): 修复关闭 codex_cli_only 无法持久化问题

在编辑 OpenAI OAuth 账号时，若 codex_cli_only 从开启切换为关闭，
现改为显式写入 false，避免 extra 为空时后端忽略更新导致旧值残留。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/account/EditAccountModal.vue

@@ -1823,6 +1823,7 @@ const handleSubmit = async () => {
     if (props.account.platform === 'openai' && (props.account.type === 'oauth' || props.account.type === 'apikey')) {
       const currentExtra = (props.account.extra as Record<string, unknown>) || {}
       const newExtra: Record<string, unknown> = { ...currentExtra }
+      const hadCodexCLIOnlyEnabled = currentExtra.codex_cli_only === true
       if (openaiPassthroughEnabled.value) {
         newExtra.openai_passthrough = true
       } else {
@@ -1830,10 +1831,15 @@ const handleSubmit = async () => {
         delete newExtra.openai_oauth_passthrough
       }
 
-      if (props.account.type === 'oauth' && codexCLIOnlyEnabled.value) {
-        newExtra.codex_cli_only = true
-      } else {
-        delete newExtra.codex_cli_only
+      if (props.account.type === 'oauth') {
+        if (codexCLIOnlyEnabled.value) {
+          newExtra.codex_cli_only = true
+        } else if (hadCodexCLIOnlyEnabled) {
+          // 关闭时显式写 false，避免 extra 为空被后端忽略导致旧值无法清除
+          newExtra.codex_cli_only = false
+        } else {
+          delete newExtra.codex_cli_only
+        }
       }
 
       updatePayload.extra = newExtra