优化聊天框状态持久化，添加 Markdown 样式支持；调整地图组件的层级，避免和聊天框冲突

src/components/olmap/core/Controls/BaseLayers.tsx

@@ -180,7 +180,7 @@ const BaseLayers: React.FC = () => {
   };
 
   return (
-    <div className="absolute right-17 bottom-11 z-1300">
+    <div className="absolute right-17 bottom-11 z-20">
       <div
         className="w-20 h-20 bg-white rounded-xl drop-shadow-xl shadow-black"
         onMouseEnter={handleEnter}

src/components/olmap/core/Controls/LayerControl.tsx

@@ -134,7 +134,7 @@ const LayerControl: React.FC = () => {
   }
 
   return (
-    <div className="absolute left-4 bottom-4 bg-white rounded-md drop-shadow-lg z-1300 opacity-85 hover:opacity-100 transition-opacity max-w-xs">
+    <div className="absolute left-4 bottom-4 bg-white rounded-md drop-shadow-lg z-20 opacity-85 hover:opacity-100 transition-opacity max-w-xs">
       <div className="ml-3 grid grid-cols-3">
         {layerItems.map((item) => (
           <FormControlLabel

src/components/olmap/core/Controls/ScaleLine.tsx

@@ -67,7 +67,7 @@ const Scale: React.FC = () => {
           }
         `}
       </style>
-      <div className="absolute bottom-0 right-0 flex items-center gap-2 px-3 py-1.5 bg-white/90 hover:bg-white rounded-tl-xl shadow-lg backdrop-blur-sm text-xs font-medium text-slate-700 z-1300 transition-all duration-300 pointer-events-auto">
+      <div className="absolute bottom-0 right-0 flex items-center gap-2 px-3 py-1.5 bg-white/90 hover:bg-white rounded-tl-xl shadow-lg backdrop-blur-sm text-xs font-medium text-slate-700 z-20 transition-all duration-300 pointer-events-auto">
         <div
           ref={scaleLineRef}
           className="custom-scale-line flex items-center justify-center min-w-[60px]"

src/components/olmap/core/Controls/Zoom.tsx

@@ -30,7 +30,7 @@ const Zoom: React.FC = () => {
   };
 
   return (
-    <div className="absolute right-4 bottom-11 z-1300">
+    <div className="absolute right-4 bottom-11 z-20">
       <div className="w-8 h-26 flex flex-col gap-2 items-center">
         <div className="w-8 h-8 bg-gray-50 flex items-center justify-center rounded-xl drop-shadow-xl shadow-black">
           <button