✨ feat: Add custom request body editor with persistent message storage

- Add CustomRequestEditor component with JSON validation and real-time formatting
- Implement bidirectional sync between chat messages and custom request body
- Add persistent local storage for chat messages (separate from config)
- Remove redundant System Prompt field in custom mode
- Refactor configuration storage to separate messages and settings

New Features:
• Custom request body mode with JSON editor and syntax highlighting
• Real-time bidirectional synchronization between chat UI and custom request body
• Persistent message storage that survives page refresh
• Enhanced configuration export/import including message data
• Improved parameter organization with collapsible sections

Technical Changes:
• Add loadMessages/saveMessages functions in configStorage
• Update usePlaygroundState hook to handle message persistence
• Refactor SettingsPanel to remove System Prompt in custom mode
• Add STORAGE_KEYS constants for better storage key management
• Implement debounced auto-save for both config and messages
• Add hash-based change detection to prevent unnecessary updates

UI/UX Improvements:
• Disabled state styling for parameters in custom mode
• Warning banners and visual feedback for mode switching
• Mobile-responsive design for custom request editor
• Consistent styling with existing design system

web/src/components/playground/OptimizedComponents.js

@@ -0,0 +1,56 @@
+import React from 'react';
+import MessageContent from './MessageContent';
+import MessageActions from './MessageActions';
+import SettingsPanel from './SettingsPanel';
+import DebugPanel from './DebugPanel';
+
+// 优化的消息内容组件
+export const OptimizedMessageContent = React.memo(MessageContent, (prevProps, nextProps) => {
+  // 只有这些属性变化时才重新渲染
+  return (
+    prevProps.message.id === nextProps.message.id &&
+    prevProps.message.content === nextProps.message.content &&
+    prevProps.message.status === nextProps.message.status &&
+    prevProps.message.isReasoningExpanded === nextProps.message.isReasoningExpanded &&
+    prevProps.isEditing === nextProps.isEditing &&
+    prevProps.editValue === nextProps.editValue &&
+    prevProps.styleState.isMobile === nextProps.styleState.isMobile
+  );
+});
+
+// 优化的消息操作组件
+export const OptimizedMessageActions = React.memo(MessageActions, (prevProps, nextProps) => {
+  return (
+    prevProps.message.id === nextProps.message.id &&
+    prevProps.isAnyMessageGenerating === nextProps.isAnyMessageGenerating &&
+    prevProps.isEditing === nextProps.isEditing
+  );
+});
+
+// 优化的设置面板组件
+export const OptimizedSettingsPanel = React.memo(SettingsPanel, (prevProps, nextProps) => {
+  return (
+    JSON.stringify(prevProps.inputs) === JSON.stringify(nextProps.inputs) &&
+    JSON.stringify(prevProps.parameterEnabled) === JSON.stringify(nextProps.parameterEnabled) &&
+    JSON.stringify(prevProps.models) === JSON.stringify(nextProps.models) &&
+    JSON.stringify(prevProps.groups) === JSON.stringify(nextProps.groups) &&
+    prevProps.customRequestMode === nextProps.customRequestMode &&
+    prevProps.customRequestBody === nextProps.customRequestBody &&
+    prevProps.showDebugPanel === nextProps.showDebugPanel &&
+    prevProps.showSettings === nextProps.showSettings &&
+    JSON.stringify(prevProps.previewPayload) === JSON.stringify(nextProps.previewPayload) &&
+    JSON.stringify(prevProps.messages) === JSON.stringify(nextProps.messages)
+  );
+});
+
+// 优化的调试面板组件
+export const OptimizedDebugPanel = React.memo(DebugPanel, (prevProps, nextProps) => {
+  return (
+    prevProps.show === nextProps.show &&
+    prevProps.activeTab === nextProps.activeTab &&
+    JSON.stringify(prevProps.debugData) === JSON.stringify(nextProps.debugData) &&
+    JSON.stringify(prevProps.previewPayload) === JSON.stringify(nextProps.previewPayload) &&
+    prevProps.customRequestMode === nextProps.customRequestMode &&
+    prevProps.showDebugPanel === nextProps.showDebugPanel
+  );
+});