style: standardize VBA property and method name casing

Standardize all VBA property and method names to lowercase for consistent code style:
- Err object: Err.Description → err.Description, Err.Number → err.Number
- Collection properties: .Count → .count
- Range properties: .Rows.Count → .Rows.count, .Row → .row
- Dictionary methods: .Keys → .keys, .Exists → .exists
- Worksheet properties: .Sheets.Count → .Sheets.count
- Fix typo: Thisworkbook.Path → ThisWorkbook.Path

VBA is case-insensitive, but consistent lowercase convention improves readability.

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

VBA_BOMConverter/Modules/M03_Logic.bas

@@ -34,7 +34,7 @@ Public Function ParseRule(strRule As String, rowIdx As Long) As Collection
     Exit Function
 
 ErrorHandler:
-    g_Logger.Record rowIdx, "M03.ParseRule", "System Error", Err.Description, strRule
+    g_Logger.Record rowIdx, "M03.ParseRule", "System Error", err.Description, strRule
     Set ParseRule = Nothing
 End Function