feat: add preprocessing module for BOM condition transformation

Add M05_PreProcessor module to handle value mapping and condition
simplification for "接头" category before parsing.

Features:
- Value mapping: azxs codes (A0/AT/AH→径向, B0/BT/BZ/BH→下轴向,
  Z0/ZT/ZZ/ZH→中轴向) and lcfw ranges (M01-M11→低压, M12-M16→高压)
- OR condition merging: automatically removes duplicate OR segments
- Smart parentheses handling: removes parentheses for single atoms,
  preserves them when needed for logical structure
- Recursive nested expression processing
- Graceful degradation when "对照表" worksheet is missing

Integration:
- Modified M01_Main to initialize preprocessor after M03_Logic
- Preprocessing applied only for "接头" category
- Updated M99_TestRunner with 8 comprehensive test cases
- All tests passing (50 total: 42 core + 8 preprocessing)

Documentation:
- Added detailed flow documentation for Test_PP_06_FullIntegration
  with mermaid diagrams in docs/Test_PP_06_FullIntegration_流程详解.md
- Updated CLAUDE.md with preprocessing module description and
  documentation guidelines (docs/ vs reference_docs/)

Example transformation:
  Input:  gclj=M16 AND (azxs=A0 OR azxs=AT) AND (lcfw=M01 OR lcfw=M15)
  Output: gclj=M16 AND azxs=径向 AND (lcfw=低压 OR lcfw=高压)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

VBA/Modules/M01_Main.bas

@@ -40,6 +40,18 @@ Public Sub RunBOMConversion()
     ' 3. 初始化逻辑模块
     M03_Logic.InitLogic logger
 
+    ' 3.1 初始化预处理模块
+    Dim wsMapping As Worksheet
+    On Error Resume Next
+    Set wsMapping = ActiveWorkbook.Sheets("对照表")
+    On Error GoTo MainErrorHandler
+
+    If wsMapping Is Nothing Then
+        MsgBox "警告：未找到 [对照表] 工作表，预处理功能将禁用。", vbExclamation
+    Else
+        M05_PreProcessor.InitPreProcessor logger, wsMapping
+    End If
+
     ' 4. 主循环
     Dim rowIdx As Long
     Dim strCat As String, strCond As String
@@ -66,6 +78,11 @@ Public Sub RunBOMConversion()
             strCond = CStr(arrData(i, M04_Config.COL_IDX_COND))
             If IsEmpty(arrData(i, M04_Config.COL_IDX_COND)) Then strCond = ""
 
+            ' 4.1 预处理条件（仅对"接头"类别）
+            If Len(strCond) > 0 And M05_PreProcessor.IsInitialized() Then
+                strCond = M05_PreProcessor.PreprocessCondition(strCond, strCat, rowIdx)
+            End If
+
             ' 解析
             Set colResult = M03_Logic.ParseRule(strCond, rowIdx)