재구성 AX Agent 설정과 채팅 UI를 Claude형 구조로

src/AxCopilot/Themes/AgentCodexDark.xaml

@@ -0,0 +1,17 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <SolidColorBrush x:Key="LauncherBackground" Color="#0B1020"/>
+    <SolidColorBrush x:Key="ItemBackground" Color="#111827"/>
+    <SolidColorBrush x:Key="ItemSelectedBackground" Color="#18233B"/>
+    <SolidColorBrush x:Key="ItemHoverBackground" Color="#132033"/>
+    <SolidColorBrush x:Key="PrimaryText" Color="#E5E7EB"/>
+    <SolidColorBrush x:Key="SecondaryText" Color="#94A3B8"/>
+    <SolidColorBrush x:Key="PlaceholderText" Color="#64748B"/>
+    <SolidColorBrush x:Key="AccentColor" Color="#60A5FA"/>
+    <SolidColorBrush x:Key="SeparatorColor" Color="#243041"/>
+    <SolidColorBrush x:Key="HintBackground" Color="#0F172A"/>
+    <SolidColorBrush x:Key="HintText" Color="#93C5FD"/>
+    <SolidColorBrush x:Key="BorderColor" Color="#2A3950"/>
+    <SolidColorBrush x:Key="ScrollbarThumb" Color="#475569"/>
+    <SolidColorBrush x:Key="ShadowColor" Color="#99000000"/>
+</ResourceDictionary>