Add complete UI layer for BOM spec addition operations

- Add frmAddSpec user form with interactive UI for spec management
- Implement dynamic checkbox generation for material name selection
- Support both macro and granular selection modes for target materials
- Add strategy selection dropdown (APPEND/CLONE)
- Add cDynamicEvent class for handling dynamic control events
- Integrate with mSpecAdditionManager for pipeline execution
- Provide real-time validation and user feedback
- Enable fine-grained control over which specific BOM rows to modify

This creates a user-friendly interface layer on top of the existing strategy pattern architecture, allowing users to visually select materials and execute spec addition operations through a graphical form instead of direct code manipulation.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

VBA/ClassModules/cDynamicEvent.cls

@@ -0,0 +1,24 @@
+' ==============================================================================
+' 模块名称: cDynamicEvent
+' 模块类别: 类模块 (Class Module)
+' 模块职责: 捕获在 Frame 中动态生成的 CheckBox 的点击事件，并触发主窗体的刷新
+' ==============================================================================
+Option Explicit
+
+' 声明一个带有事件的复选框对象
+Public WithEvents dynCheckBox As MSForms.CheckBox
+
+' 指向主窗体的引用，用于调用主窗体的方法
+Public parentForm As Object
+
+' ------------------------------------------------------------------------------
+' 当动态生成的复选框被点击时，触发此事件
+' ------------------------------------------------------------------------------
+Private Sub dynCheckBox_Click()
+    ' 如果父窗体存在，且用户勾选了"显示具体物料"，则通知父窗体刷新下方列表
+    If Not parentForm Is Nothing Then
+        If parentForm.chkShowDetails.value = True Then
+            parentForm.RefreshDetailsPanel
+        End If
+    End If
+End Sub