feat(settings): per-provider "Reasoning depth" dropdown

New UI control in Settings → Providers, rendered on every active /
key-present provider row directly below the model selector. Writes
through `config:v1:update-provider` with tri-state semantics:

- "Default (auto)"  →  null  →  clears override; core picks the default
- any level string  →  sets ProviderEntry.reasoningLevel
- the field flows into GenerateInput.reasoningLevel at call time

Claude Code imports pre-seed "medium" so consumer-tier proxies work
out of the box; users on higher-tier plans can now raise it to high /
xhigh without editing config.toml by hand.

- preload updateProvider gains reasoningLevel?: ReasoningLevel | null
- Settings.tsx: ReasoningDepthSelector component (dropdown + save)
- i18n en / zh-CN: settings.providers.reasoning.* + toast strings

Author: hqhq1025

apps/desktop/src/preload/index.ts

@@ -290,6 +290,9 @@ const api = {
       wire?: WireApi;
       httpHeaders?: Record<string, string>;
       queryParams?: Record<string, string>;
+      /** `null` explicitly clears the override and falls back to the model
+       *  default; a level string sets it; omit to leave untouched. */
+      reasoningLevel?: ReasoningLevel | null;
     }) => ipcRenderer.invoke('config:v1:update-provider', input) as Promise<OnboardingState>,
     removeProvider: (id: string) =>
       ipcRenderer.invoke('config:v1:remove-provider', id) as Promise<OnboardingState>,

apps/desktop/src/renderer/src/components/Settings.tsx

@@ -1,5 +1,5 @@
 import { setLocale as applyLocale, useT } from '@open-codesign/i18n';
-import type { OnboardingState } from '@open-codesign/shared';
+import type { OnboardingState, ReasoningLevel } from '@open-codesign/shared';
 import {
   PROVIDER_SHORTLIST as SHORTLIST,
   isSupportedOnboardingProvider,
@@ -355,6 +355,18 @@ function ProviderCard({
       {row.isActive && !hasError && config !== null && (
         <ActiveModelSelector config={config} provider={row.provider} />
       )}
+      {!hasError && row.hasKey !== false && (
+        <ReasoningDepthSelector
+          provider={row.provider}
+          value={row.reasoningLevel}
+          onUpdated={(nextRow) => {
+            // Fire-and-forget refresh of parent rows list is handled by the
+            // callback set in ProvidersList; this component just needs to
+            // let the parent know a write succeeded.
+            void nextRow;
+          }}
+        />
+      )}
     </div>
   );
 }
@@ -444,6 +456,70 @@ function ActiveModelSelector({
   );
 }
 
+type ReasoningOption = '' | 'minimal' | 'low' | 'medium' | 'high' | 'xhigh';
+
+function ReasoningDepthSelector({
+  provider,
+  value,
+  onUpdated,
+}: {
+  provider: string;
+  value: ReasoningLevel | undefined;
+  onUpdated: (row: ProviderRow) => void;
+}) {
+  const t = useT();
+  const pushToast = useCodesignStore((s) => s.pushToast);
+  const [saving, setSaving] = useState(false);
+
+  async function handleChange(next: ReasoningOption) {
+    if (!window.codesign?.config?.updateProvider) return;
+    setSaving(true);
+    try {
+      // '' means "clear the per-provider override and fall back to the
+      // model-family default"; any other string is an explicit set.
+      const payload = { id: provider, reasoningLevel: next === '' ? null : next } as const;
+      await window.codesign.config.updateProvider(payload);
+      pushToast({ variant: 'success', title: t('settings.providers.toast.reasoningSaved') });
+      if (window.codesign?.settings?.listProviders) {
+        const rows = await window.codesign.settings.listProviders();
+        const row = rows.find((r) => r.provider === provider);
+        if (row) onUpdated(row);
+      }
+    } catch (err) {
+      pushToast({
+        variant: 'error',
+        title: t('settings.providers.toast.reasoningSaveFailed'),
+        description: err instanceof Error ? err.message : t('settings.common.unknownError'),
+      });
+    } finally {
+      setSaving(false);
+    }
+  }
+
+  const current: ReasoningOption = value ?? '';
+  const options: Array<{ value: ReasoningOption; label: string }> = [
+    { value: '', label: t('settings.providers.reasoning.default') },
+    { value: 'minimal', label: t('settings.providers.reasoning.minimal') },
+    { value: 'low', label: t('settings.providers.reasoning.low') },
+    { value: 'medium', label: t('settings.providers.reasoning.medium') },
+    { value: 'high', label: t('settings.providers.reasoning.high') },
+    { value: 'xhigh', label: t('settings.providers.reasoning.xhigh') },
+  ];
+
+  return (
+    <div className="mt-[var(--space-2)] flex items-center gap-[var(--space-2)] text-[var(--text-xs)] text-[var(--color-text-muted)]">
+      <Sliders className="w-3 h-3 shrink-0" />
+      <span>{t('settings.providers.reasoning.label')}</span>
+      <NativeSelect
+        value={current}
+        onChange={(v) => void handleChange(v as ReasoningOption)}
+        options={options}
+        disabled={saving}
+      />
+    </div>
+  );
+}
+
 const DISMISSED_BANNER_PREFIX = 'open-codesign:settings:dismissed-import-banner:';
 function readDismissed(kind: 'codex' | 'claudeCode'): boolean {
   try {

packages/i18n/src/locales/en.json

@@ -62,18 +62,16 @@
     "error": {
       "title": "Generation failed",
       "body": "Something went wrong while generating your design.",
-      "copyError": "Copy error details"
+      "copyError": "Copy error details",
+      "brokenJsx": "This design has a syntax error, likely an incomplete early save. Regenerate or edit to fix.",
+      "undefinedRef": "The design references an undefined variable or component. Likely a mid-run abort — try regenerating."
     },
     "ready": "Preview",
     "noDesign": "No design yet",
     "clickToComment": "Click any element in the preview to leave an inline comment.",
     "commentMode": "Comment mode",
     "commentModeHint": "Click any element to comment",
     "runtimeError": "Preview runtime error",
-    "error": {
-      "brokenJsx": "This design has a syntax error, likely an incomplete early save. Regenerate or edit to fix.",
-      "undefinedRef": "The design references an undefined variable or component. Likely a mid-run abort — try regenerating."
-    },
     "dismissErrors": "Dismiss preview errors",
     "zoom": "Zoom"
   },
@@ -234,8 +232,19 @@
         "switchFailed": "Switch failed",
         "saved": "Provider saved",
         "modelSaveFailed": "Failed to save model selection",
+        "reasoningSaved": "Reasoning depth saved",
+        "reasoningSaveFailed": "Failed to save reasoning depth",
         "connectionOk": "Connection OK",
         "connectionFailed": "Connection failed"
+      },
+      "reasoning": {
+        "label": "Reasoning depth",
+        "default": "Default (auto)",
+        "minimal": "Minimal",
+        "low": "Low",
+        "medium": "Medium",
+        "high": "High",
+        "xhigh": "Extra high"
       }
     },
     "appearance": {

packages/i18n/src/locales/zh-CN.json

@@ -39,7 +39,6 @@
     "previewHint": "缩略预览 · 双击文件名或点击「在新标签打开」可在独立标签查看",
     "tabsAriaLabel": "已打开文件",
     "closeTab": "关闭 {{name}}",
-    "closeTab": "关闭 {{name}}",
     "files": {
       "sectionTitle": "设计文件",
       "sectionSubtitle": "共 {{count}} 个文件",
@@ -64,18 +63,16 @@
     "error": {
       "title": "生成失败",
       "body": "生成过程中出错了。",
-      "copyError": "复制错误详情"
+      "copyError": "复制错误详情",
+      "brokenJsx": "此设计的代码有语法错误，可能是早期版本保存的不完整内容。重新生成或编辑修复即可。",
+      "undefinedRef": "设计引用了未定义的变量或组件。可能是生成中途中断——尝试重新生成。"
     },
     "ready": "预览",
     "noDesign": "还没有设计",
     "clickToComment": "点击预览中的任意元素即可留下局部评论。",
     "commentMode": "评论模式",
     "commentModeHint": "点击任意元素留评",
     "runtimeError": "预览运行时错误",
-    "error": {
-      "brokenJsx": "此设计的代码有语法错误，可能是早期版本保存的不完整内容。重新生成或编辑修复即可。",
-      "undefinedRef": "设计引用了未定义的变量或组件。可能是生成中途中断——尝试重新生成。"
-    },
     "dismissErrors": "关闭预览错误",
     "zoom": "缩放"
   },
@@ -238,8 +235,19 @@
         "switchFailed": "切换失败",
         "saved": "服务已保存",
         "modelSaveFailed": "保存模型选择失败",
+        "reasoningSaved": "已保存推理深度",
+        "reasoningSaveFailed": "保存推理深度失败",
         "connectionOk": "连接正常",
         "connectionFailed": "连接失败"
+      },
+      "reasoning": {
+        "label": "推理深度",
+        "default": "默认（自动）",
+        "minimal": "极低",
+        "low": "低",
+        "medium": "中",
+        "high": "高",
+        "xhigh": "最高"
       }
     },
     "appearance": {