refactor: standardize variable naming and file formatting

- Rename Quantity to quantity in BomItem for consistent naming convention
- Update references in MainModule to use lowercase quantity
- Add newlines at end of files for consistency
- Update vba_metadata.json with new source path and document module

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

VBA/Modules/BIPUploadModule.bas

@@ -419,4 +419,4 @@ Private Sub FormatBIPSheet(ws As Worksheet)
     ws.Columns(7).NumberFormat = "yyyy/mm/dd"
 
     On Error GoTo 0
-End Sub
+End Sub