Add xlsxwriter-based Excel generation scripts with openpyxl implementation

- Created create_excel_xlsxwriter.py and update_excel_xlsxwriter.py
- Uses openpyxl exclusively to preserve Excel formatting and formulas
- Updated server.js to use new xlsxwriter scripts for form submissions
- Maintains all original functionality while ensuring proper Excel file handling

🤖 Generated with [Claude Code](https://claude.ai/code)

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

venv/bin/vba_extract.py

@@ -0,0 +1,79 @@
+#!/home/pixot/business_case_form/venv/bin/python3
+
+##############################################################################
+#
+# vba_extract - A simple utility to extract a vbaProject.bin binary from an
+# Excel 2007+ xlsm file for insertion into an XlsxWriter file.
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2013-2025, John McNamara, jmcnamara@cpan.org
+#
+
+import sys
+from zipfile import BadZipFile, ZipFile
+
+
+def extract_file(xlsm_zip, filename):
+    # Extract a single file from an Excel xlsm macro file.
+    data = xlsm_zip.read("xl/" + filename)
+
+    # Write the data to a local file.
+    file = open(filename, "wb")
+    file.write(data)
+    file.close()
+
+
+# The VBA project file and project signature file we want to extract.
+vba_filename = "vbaProject.bin"
+vba_signature_filename = "vbaProjectSignature.bin"
+
+# Get the xlsm file name from the commandline.
+if len(sys.argv) > 1:
+    xlsm_file = sys.argv[1]
+else:
+    print(
+        "\nUtility to extract a vbaProject.bin binary from an Excel 2007+ "
+        "xlsm macro file for insertion into an XlsxWriter file.\n"
+        "If the macros are digitally signed, extracts also a vbaProjectSignature.bin "
+        "file.\n"
+        "\n"
+        "See: https://xlsxwriter.readthedocs.io/working_with_macros.html\n"
+        "\n"
+        "Usage: vba_extract file.xlsm\n"
+    )
+    sys.exit()
+
+try:
+    # Open the Excel xlsm file as a zip file.
+    xlsm_zip = ZipFile(xlsm_file, "r")
+
+    # Read the xl/vbaProject.bin file.
+    extract_file(xlsm_zip, vba_filename)
+    print(f"Extracted: {vba_filename}")
+
+    if "xl/" + vba_signature_filename in xlsm_zip.namelist():
+        extract_file(xlsm_zip, vba_signature_filename)
+        print(f"Extracted: {vba_signature_filename}")
+
+
+except IOError as e:
+    print(f"File error: {str(e)}")
+    sys.exit()
+
+except KeyError as e:
+    # Usually when there isn't a xl/vbaProject.bin member in the file.
+    print(f"File error: {str(e)}")
+    print(f"File may not be an Excel xlsm macro file: '{xlsm_file}'")
+    sys.exit()
+
+except BadZipFile as e:
+    # Usually if the file is an xls file and not an xlsm file.
+    print(f"File error: {str(e)}: '{xlsm_file}'")
+    print("File may not be an Excel xlsm macro file.")
+    sys.exit()
+
+except Exception as e:
+    # Catch any other exceptions.
+    print(f"File error: {str(e)}")
+    sys.exit()