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/lib/python3.12/site-packages/xlsxwriter/chart_doughnut.py

@@ -0,0 +1,101 @@
+###############################################################################
+#
+# ChartDoughnut - A class for writing the Excel XLSX Doughnut charts.
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2013-2025, John McNamara, jmcnamara@cpan.org
+#
+
+from warnings import warn
+
+from . import chart_pie
+
+
+class ChartDoughnut(chart_pie.ChartPie):
+    """
+    A class for writing the Excel XLSX Doughnut charts.
+
+
+    """
+
+    ###########################################################################
+    #
+    # Public API.
+    #
+    ###########################################################################
+
+    def __init__(self) -> None:
+        """
+        Constructor.
+
+        """
+        super().__init__()
+
+        self.vary_data_color = 1
+        self.rotation = 0
+        self.hole_size = 50
+
+    def set_hole_size(self, size: int) -> None:
+        """
+        Set the Doughnut chart hole size.
+
+        Args:
+            size: 10 <= size <= 90.
+
+        Returns:
+            Nothing.
+
+        """
+        if size is None:
+            return
+
+        # Ensure the size is in Excel's range.
+        if size < 10 or size > 90:
+            warn("Chart hole size '{size}' outside Excel range: 10 <= size <= 90")
+            return
+
+        self.hole_size = int(size)
+
+    ###########################################################################
+    #
+    # Private API.
+    #
+    ###########################################################################
+
+    def _write_chart_type(self, args) -> None:
+        # Override the virtual superclass method with a chart specific method.
+        # Write the c:doughnutChart element.
+        self._write_doughnut_chart()
+
+    ###########################################################################
+    #
+    # XML methods.
+    #
+    ###########################################################################
+
+    def _write_doughnut_chart(self) -> None:
+        # Write the <c:doughnutChart> element.  Over-ridden method to remove
+        # axis_id code since Doughnut charts don't require val and cat axes.
+        self._xml_start_tag("c:doughnutChart")
+
+        # Write the c:varyColors element.
+        self._write_vary_colors()
+
+        # Write the series elements.
+        for data in self.series:
+            self._write_ser(data)
+
+        # Write the c:firstSliceAng element.
+        self._write_first_slice_ang()
+
+        # Write the c:holeSize element.
+        self._write_c_hole_size()
+
+        self._xml_end_tag("c:doughnutChart")
+
+    def _write_c_hole_size(self) -> None:
+        # Write the <c:holeSize> element.
+        attributes = [("val", self.hole_size)]
+
+        self._xml_empty_tag("c:holeSize", attributes)