接入菜单导航并改造通用按钮交互

- 将 CommonButton 改为基于 Unity Button 实现，保留原有 pointer enter、click、pointer exit 三类事件配置，同时接入 Selectable/Button 的导航、选中和提交能力。补充 CommonButton 自定义 Inspector，保留项目自定义事件与背景配置的编辑体验。

- 同步调整菜单相关 UI，将 StartMenuForm 迁移为 MenuForm，并更新 UIForm 配置、菜单 Controller/Form 以及相关 prefab 引用。更新多个 UI prefab 和通用按钮 prefab，使菜单、商店、角色选择、道具展示等界面能够使用新的按钮选中与导航交互。

Assets/GameMain/UI/UIItems/CommonButton.prefab

@@ -269,33 +269,42 @@ MonoBehaviour:
   m_Script: {fileID: 11500000, guid: a5079836f95c2a44b96fa331487ebb70, type: 3}
   m_Name: 
   m_EditorClassIdentifier: 
-  _onHoverAction:
+  m_Navigation:
+    m_Mode: 3
+    m_WrapAround: 0
+    m_SelectOnUp: {fileID: 0}
+    m_SelectOnDown: {fileID: 0}
+    m_SelectOnLeft: {fileID: 0}
+    m_SelectOnRight: {fileID: 0}
+  m_Transition: 0
+  m_Colors:
+    m_NormalColor: {r: 1, g: 1, b: 1, a: 1}
+    m_HighlightedColor: {r: 0.9607843, g: 0.9607843, b: 0.9607843, a: 1}
+    m_PressedColor: {r: 0.78431374, g: 0.78431374, b: 0.78431374, a: 1}
+    m_SelectedColor: {r: 0.9607843, g: 0.9607843, b: 0.9607843, a: 1}
+    m_DisabledColor: {r: 0.78431374, g: 0.78431374, b: 0.78431374, a: 0.5019608}
+    m_ColorMultiplier: 1
+    m_FadeDuration: 0.1
+  m_SpriteState:
+    m_HighlightedSprite: {fileID: 0}
+    m_PressedSprite: {fileID: 0}
+    m_SelectedSprite: {fileID: 0}
+    m_DisabledSprite: {fileID: 0}
+  m_AnimationTriggers:
+    m_NormalTrigger: Normal
+    m_HighlightedTrigger: Highlighted
+    m_PressedTrigger: Pressed
+    m_SelectedTrigger: Selected
+    m_DisabledTrigger: Disabled
+  m_Interactable: 1
+  m_TargetGraphic: {fileID: 0}
+  m_OnClick:
     m_PersistentCalls:
-      m_Calls:
-      - m_Target: {fileID: 0}
-        m_TargetAssemblyTypeName: 
-        m_MethodName: 
-        m_Mode: 0
-        m_Arguments:
-          m_ObjectArgument: {fileID: 0}
-          m_ObjectArgumentAssemblyTypeName: 
-          m_IntArgument: 0
-          m_FloatArgument: 0
-          m_StringArgument: 
-          m_BoolArgument: 0
-        m_CallState: 2
-      - m_Target: {fileID: 0}
-        m_TargetAssemblyTypeName: 
-        m_MethodName: 
-        m_Mode: 0
-        m_Arguments:
-          m_ObjectArgument: {fileID: 0}
-          m_ObjectArgumentAssemblyTypeName: 
-          m_IntArgument: 0
-          m_FloatArgument: 0
-          m_StringArgument: 
-          m_BoolArgument: 0
-        m_CallState: 2
+      m_Calls: []
+  _background: {fileID: 3719248416810234768}
+  _onPointerEnterAction:
+    m_PersistentCalls:
+      m_Calls: []
   _onClickAction:
     m_PersistentCalls:
       m_Calls:
@@ -311,3 +320,6 @@ MonoBehaviour:
           m_StringArgument: 
           m_BoolArgument: 0
         m_CallState: 2
+  _onPointerExitAction:
+    m_PersistentCalls:
+      m_Calls: []