feat(ui): add merge preview to common config editor components

Add real-time merge preview functionality to all config editor components
(Claude, Codex, Gemini) that shows the final merged configuration when
common config is enabled.

UI changes:
- Add finalConfig/finalEnv prop to display merged result
- Add toggle button to show/hide merge preview (Eye/EyeOff icons)
- Auto-show preview when common config is enabled
- Display custom config editor with label when preview is visible
- Show read-only merged preview below custom config
- Add visual indicators: "只读" badge, green hint text

The preview helps users understand how their custom configuration
combines with the shared common config template before saving.

src/components/providers/forms/CodexConfigEditor.tsx

@@ -30,6 +30,9 @@ interface CodexConfigEditorProps {
   onExtract?: () => void;
 
   isExtracting?: boolean;
+
+  /** 最终合并后的配置（只读预览） */
+  finalConfig?: string;
 }
 
 const CodexConfigEditor: React.FC<CodexConfigEditorProps> = ({
@@ -47,6 +50,7 @@ const CodexConfigEditor: React.FC<CodexConfigEditorProps> = ({
   configError,
   onExtract,
   isExtracting,
+  finalConfig,
 }) => {
   const [isCommonConfigModalOpen, setIsCommonConfigModalOpen] = useState(false);
 
@@ -76,6 +80,7 @@ const CodexConfigEditor: React.FC<CodexConfigEditorProps> = ({
         onEditCommonConfig={() => setIsCommonConfigModalOpen(true)}
         commonConfigError={commonConfigError}
         configError={configError}
+        finalConfig={finalConfig}
       />
 
       {/* Common Config Modal */}

src/components/providers/forms/CodexConfigSections.tsx

@@ -1,6 +1,8 @@
 import React, { useEffect, useState } from "react";
 import { useTranslation } from "react-i18next";
+import { Eye, EyeOff } from "lucide-react";
 import JsonEditor from "@/components/JsonEditor";
+import { Label } from "@/components/ui/label";
 
 interface CodexAuthSectionProps {
   value: string;
@@ -83,6 +85,8 @@ interface CodexConfigSectionProps {
   onEditCommonConfig: () => void;
   commonConfigError?: string;
   configError?: string;
+  /** 最终合并后的配置（只读预览） */
+  finalConfig?: string;
 }
 
 /**
@@ -96,9 +100,11 @@ export const CodexConfigSection: React.FC<CodexConfigSectionProps> = ({
   onEditCommonConfig,
   commonConfigError,
   configError,
+  finalConfig,
 }) => {
   const { t } = useTranslation();
   const [isDarkMode, setIsDarkMode] = useState(false);
+  const [showPreview, setShowPreview] = useState(false);
 
   useEffect(() => {
     setIsDarkMode(document.documentElement.classList.contains("dark"));
@@ -115,6 +121,13 @@ export const CodexConfigSection: React.FC<CodexConfigSectionProps> = ({
     return () => observer.disconnect();
   }, []);
 
+  // 当启用通用配置时，自动显示预览
+  useEffect(() => {
+    if (useCommonConfig && finalConfig) {
+      setShowPreview(true);
+    }
+  }, [useCommonConfig, finalConfig]);
+
   return (
     <div className="space-y-2">
       <div className="flex items-center justify-between">
@@ -136,7 +149,32 @@ export const CodexConfigSection: React.FC<CodexConfigSectionProps> = ({
         </label>
       </div>
 
-      <div className="flex items-center justify-end">
+      <div className="flex items-center justify-between">
+        <div className="flex items-center gap-2">
+          {useCommonConfig && finalConfig && (
+            <button
+              type="button"
+              onClick={() => setShowPreview(!showPreview)}
+              className="inline-flex items-center gap-1 text-xs text-blue-400 dark:text-blue-500 hover:text-blue-500 dark:hover:text-blue-400 transition-colors"
+            >
+              {showPreview ? (
+                <>
+                  <EyeOff className="w-3 h-3" />
+                  {t("codexConfig.hidePreview", {
+                    defaultValue: "隐藏合并预览",
+                  })}
+                </>
+              ) : (
+                <>
+                  <Eye className="w-3 h-3" />
+                  {t("codexConfig.showPreview", {
+                    defaultValue: "显示合并预览",
+                  })}
+                </>
+              )}
+            </button>
+          )}
+        </div>
         <button
           type="button"
           onClick={onEditCommonConfig}
@@ -152,15 +190,57 @@ export const CodexConfigSection: React.FC<CodexConfigSectionProps> = ({
         </p>
       )}
 
-      <JsonEditor
-        value={value}
-        onChange={onChange}
-        placeholder=""
-        darkMode={isDarkMode}
-        rows={8}
-        showValidation={false}
-        language="javascript"
-      />
+      {/* 自定义配置编辑器 */}
+      <div className="space-y-1">
+        {useCommonConfig && showPreview && (
+          <Label className="text-xs text-muted-foreground">
+            {t("codexConfig.customConfig", {
+              defaultValue: "自定义配置（覆盖通用配置）",
+            })}
+          </Label>
+        )}
+        <JsonEditor
+          value={value}
+          onChange={onChange}
+          placeholder=""
+          darkMode={isDarkMode}
+          rows={useCommonConfig && showPreview ? 6 : 8}
+          showValidation={false}
+          language="javascript"
+        />
+      </div>
+
+      {/* 合并预览（只读）- 放在自定义配置下面 */}
+      {useCommonConfig && showPreview && finalConfig && (
+        <div className="space-y-1">
+          <div className="flex items-center justify-between">
+            <Label className="text-xs text-muted-foreground">
+              {t("codexConfig.mergedPreview", {
+                defaultValue: "合并预览（只读）",
+              })}
+            </Label>
+            <span className="text-xs text-green-500 dark:text-green-400">
+              {t("codexConfig.mergedPreviewHint", {
+                defaultValue: "通用配置 + 自定义配置 = 最终配置",
+              })}
+            </span>
+          </div>
+          <div className="relative">
+            <JsonEditor
+              value={finalConfig}
+              onChange={() => {}} // 只读
+              darkMode={isDarkMode}
+              rows={6}
+              showValidation={false}
+              language="javascript"
+              readOnly={true}
+            />
+            <div className="absolute top-2 right-2 px-2 py-0.5 bg-green-500/10 text-green-600 dark:text-green-400 text-xs rounded">
+              {t("common.readonly", { defaultValue: "只读" })}
+            </div>
+          </div>
+        </div>
+      )}
 
       {configError && (
         <p className="text-xs text-red-500 dark:text-red-400">{configError}</p>

src/components/providers/forms/CommonConfigEditor.tsx

@@ -3,7 +3,7 @@ import { useEffect, useState } from "react";
 import { FullScreenPanel } from "@/components/common/FullScreenPanel";
 import { Label } from "@/components/ui/label";
 import { Button } from "@/components/ui/button";
-import { Save, Download, Loader2 } from "lucide-react";
+import { Save, Download, Loader2, Eye, EyeOff } from "lucide-react";
 import JsonEditor from "@/components/JsonEditor";
 
 interface CommonConfigEditorProps {
@@ -19,6 +19,8 @@ interface CommonConfigEditorProps {
   onModalClose: () => void;
   onExtract?: () => void;
   isExtracting?: boolean;
+  /** 最终合并后的配置（只读预览） */
+  finalConfig?: string;
 }
 
 export function CommonConfigEditor({
@@ -34,9 +36,11 @@ export function CommonConfigEditor({
   onModalClose,
   onExtract,
   isExtracting,
+  finalConfig,
 }: CommonConfigEditorProps) {
   const { t } = useTranslation();
   const [isDarkMode, setIsDarkMode] = useState(false);
+  const [showPreview, setShowPreview] = useState(false);
 
   useEffect(() => {
     setIsDarkMode(document.documentElement.classList.contains("dark"));
@@ -53,6 +57,13 @@ export function CommonConfigEditor({
     return () => observer.disconnect();
   }, []);
 
+  // 当启用通用配置时，自动显示预览
+  useEffect(() => {
+    if (useCommonConfig && finalConfig) {
+      setShowPreview(true);
+    }
+  }, [useCommonConfig, finalConfig]);
+
   return (
     <>
       <div className="space-y-2">
@@ -75,7 +86,32 @@ export function CommonConfigEditor({
             </label>
           </div>
         </div>
-        <div className="flex items-center justify-end">
+        <div className="flex items-center justify-between">
+          <div className="flex items-center gap-2">
+            {useCommonConfig && finalConfig && (
+              <button
+                type="button"
+                onClick={() => setShowPreview(!showPreview)}
+                className="inline-flex items-center gap-1 text-xs text-blue-400 dark:text-blue-500 hover:text-blue-500 dark:hover:text-blue-400 transition-colors"
+              >
+                {showPreview ? (
+                  <>
+                    <EyeOff className="w-3 h-3" />
+                    {t("claudeConfig.hidePreview", {
+                      defaultValue: "隐藏合并预览",
+                    })}
+                  </>
+                ) : (
+                  <>
+                    <Eye className="w-3 h-3" />
+                    {t("claudeConfig.showPreview", {
+                      defaultValue: "显示合并预览",
+                    })}
+                  </>
+                )}
+              </button>
+            )}
+          </div>
           <button
             type="button"
             onClick={onEditClick}
@@ -91,20 +127,63 @@ export function CommonConfigEditor({
             {commonConfigError}
           </p>
         )}
-        <JsonEditor
-          value={value}
-          onChange={onChange}
-          placeholder={`{
+
+        {/* 自定义配置编辑器 */}
+        <div className="space-y-1">
+          {useCommonConfig && showPreview && (
+            <Label className="text-xs text-muted-foreground">
+              {t("claudeConfig.customConfig", {
+                defaultValue: "自定义配置（覆盖通用配置）",
+              })}
+            </Label>
+          )}
+          <JsonEditor
+            value={value}
+            onChange={onChange}
+            placeholder={`{
   "env": {
     "ANTHROPIC_BASE_URL": "https://your-api-endpoint.com",
     "ANTHROPIC_AUTH_TOKEN": "your-api-key-here"
   }
 }`}
-          darkMode={isDarkMode}
-          rows={14}
-          showValidation={true}
-          language="json"
-        />
+            darkMode={isDarkMode}
+            rows={useCommonConfig && showPreview ? 10 : 14}
+            showValidation={true}
+            language="json"
+          />
+        </div>
+
+        {/* 合并预览（只读）- 放在自定义配置下面 */}
+        {useCommonConfig && showPreview && finalConfig && (
+          <div className="space-y-1">
+            <div className="flex items-center justify-between">
+              <Label className="text-xs text-muted-foreground">
+                {t("claudeConfig.mergedPreview", {
+                  defaultValue: "合并预览（只读）",
+                })}
+              </Label>
+              <span className="text-xs text-green-500 dark:text-green-400">
+                {t("claudeConfig.mergedPreviewHint", {
+                  defaultValue: "通用配置 + 自定义配置 = 最终配置",
+                })}
+              </span>
+            </div>
+            <div className="relative">
+              <JsonEditor
+                value={finalConfig}
+                onChange={() => {}} // 只读
+                darkMode={isDarkMode}
+                rows={8}
+                showValidation={false}
+                language="json"
+                readOnly={true}
+              />
+              <div className="absolute top-2 right-2 px-2 py-0.5 bg-green-500/10 text-green-600 dark:text-green-400 text-xs rounded">
+                {t("common.readonly", { defaultValue: "只读" })}
+              </div>
+            </div>
+          </div>
+        )}
       </div>
 
       <FullScreenPanel

src/components/providers/forms/GeminiConfigEditor.tsx

@@ -17,6 +17,8 @@ interface GeminiConfigEditorProps {
   configError: string;
   onExtract?: () => void;
   isExtracting?: boolean;
+  /** 最终合并后的 env 配置（只读预览） */
+  finalEnv?: string;
 }
 
 const GeminiConfigEditor: React.FC<GeminiConfigEditorProps> = ({
@@ -34,6 +36,7 @@ const GeminiConfigEditor: React.FC<GeminiConfigEditorProps> = ({
   configError,
   onExtract,
   isExtracting,
+  finalEnv,
 }) => {
   const [isCommonConfigModalOpen, setIsCommonConfigModalOpen] = useState(false);
 
@@ -56,6 +59,7 @@ const GeminiConfigEditor: React.FC<GeminiConfigEditorProps> = ({
         onCommonConfigToggle={onCommonConfigToggle}
         onEditCommonConfig={() => setIsCommonConfigModalOpen(true)}
         commonConfigError={commonConfigError}
+        finalEnv={finalEnv}
       />
 
       {/* Config JSON Section */}

src/components/providers/forms/GeminiConfigSections.tsx

@@ -1,6 +1,8 @@
 import React, { useEffect, useState } from "react";
 import { useTranslation } from "react-i18next";
+import { Eye, EyeOff } from "lucide-react";
 import JsonEditor from "@/components/JsonEditor";
+import { Label } from "@/components/ui/label";
 
 interface GeminiEnvSectionProps {
   value: string;
@@ -11,6 +13,8 @@ interface GeminiEnvSectionProps {
   onCommonConfigToggle: (checked: boolean) => void;
   onEditCommonConfig: () => void;
   commonConfigError?: string;
+  /** 最终合并后的 env 配置（只读预览） */
+  finalEnv?: string;
 }
 
 /**
@@ -25,9 +29,11 @@ export const GeminiEnvSection: React.FC<GeminiEnvSectionProps> = ({
   onCommonConfigToggle,
   onEditCommonConfig,
   commonConfigError,
+  finalEnv,
 }) => {
   const { t } = useTranslation();
   const [isDarkMode, setIsDarkMode] = useState(false);
+  const [showPreview, setShowPreview] = useState(false);
 
   useEffect(() => {
     setIsDarkMode(document.documentElement.classList.contains("dark"));
@@ -44,6 +50,13 @@ export const GeminiEnvSection: React.FC<GeminiEnvSectionProps> = ({
     return () => observer.disconnect();
   }, []);
 
+  // 当启用通用配置时，自动显示预览
+  useEffect(() => {
+    if (useCommonConfig && finalEnv) {
+      setShowPreview(true);
+    }
+  }, [useCommonConfig, finalEnv]);
+
   const handleChange = (newValue: string) => {
     onChange(newValue);
     if (onBlur) {
@@ -74,7 +87,32 @@ export const GeminiEnvSection: React.FC<GeminiEnvSectionProps> = ({
         </label>
       </div>
 
-      <div className="flex items-center justify-end">
+      <div className="flex items-center justify-between">
+        <div className="flex items-center gap-2">
+          {useCommonConfig && finalEnv && (
+            <button
+              type="button"
+              onClick={() => setShowPreview(!showPreview)}
+              className="inline-flex items-center gap-1 text-xs text-blue-400 dark:text-blue-500 hover:text-blue-500 dark:hover:text-blue-400 transition-colors"
+            >
+              {showPreview ? (
+                <>
+                  <EyeOff className="w-3 h-3" />
+                  {t("geminiConfig.hidePreview", {
+                    defaultValue: "隐藏合并预览",
+                  })}
+                </>
+              ) : (
+                <>
+                  <Eye className="w-3 h-3" />
+                  {t("geminiConfig.showPreview", {
+                    defaultValue: "显示合并预览",
+                  })}
+                </>
+              )}
+            </button>
+          )}
+        </div>
         <button
           type="button"
           onClick={onEditCommonConfig}
@@ -92,17 +130,59 @@ export const GeminiEnvSection: React.FC<GeminiEnvSectionProps> = ({
         </p>
       )}
 
-      <JsonEditor
-        value={value}
-        onChange={handleChange}
-        placeholder={`GOOGLE_GEMINI_BASE_URL=https://your-api-endpoint.com/
+      {/* 自定义配置编辑器 */}
+      <div className="space-y-1">
+        {useCommonConfig && showPreview && (
+          <Label className="text-xs text-muted-foreground">
+            {t("geminiConfig.customConfig", {
+              defaultValue: "自定义配置（覆盖通用配置）",
+            })}
+          </Label>
+        )}
+        <JsonEditor
+          value={value}
+          onChange={handleChange}
+          placeholder={`GOOGLE_GEMINI_BASE_URL=https://your-api-endpoint.com/
 GEMINI_API_KEY=sk-your-api-key-here
 GEMINI_MODEL=gemini-3-pro-preview`}
-        darkMode={isDarkMode}
-        rows={6}
-        showValidation={false}
-        language="javascript"
-      />
+          darkMode={isDarkMode}
+          rows={useCommonConfig && showPreview ? 4 : 6}
+          showValidation={false}
+          language="javascript"
+        />
+      </div>
+
+      {/* 合并预览（只读）- 放在自定义配置下面 */}
+      {useCommonConfig && showPreview && finalEnv && (
+        <div className="space-y-1">
+          <div className="flex items-center justify-between">
+            <Label className="text-xs text-muted-foreground">
+              {t("geminiConfig.mergedPreview", {
+                defaultValue: "合并预览（只读）",
+              })}
+            </Label>
+            <span className="text-xs text-green-500 dark:text-green-400">
+              {t("geminiConfig.mergedPreviewHint", {
+                defaultValue: "通用配置 + 自定义配置 = 最终配置",
+              })}
+            </span>
+          </div>
+          <div className="relative">
+            <JsonEditor
+              value={finalEnv}
+              onChange={() => {}} // 只读
+              darkMode={isDarkMode}
+              rows={4}
+              showValidation={false}
+              language="javascript"
+              readOnly={true}
+            />
+            <div className="absolute top-2 right-2 px-2 py-0.5 bg-green-500/10 text-green-600 dark:text-green-400 text-xs rounded">
+              {t("common.readonly", { defaultValue: "只读" })}
+            </div>
+          </div>
+        </div>
+      )}
 
       {error && (
         <p className="text-xs text-red-500 dark:text-red-400">{error}</p>