Clean up codebase and restore stable Excel processing

- Removed outdated Excel processing scripts and documentation files
- Kept only update_excel_xlsxwriter.py as the primary Excel processor
- Restored stable configuration with working minimarket support
- Optimized HTTP headers for better file delivery

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

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

update_excel_xlsxwriter.py

@@ -35,6 +35,7 @@ def update_excel_variables(excel_path):
         print(f"Opening Excel file: {excel_path}")
         wb = openpyxl.load_workbook(excel_path)
 
+
         # Break any external links to prevent unsafe external sources error
         print("Breaking any external links...")
         try:
@@ -156,6 +157,7 @@ def update_excel_variables(excel_path):
         print("Forcing formula recalculation...")
         wb.calculation.calcMode = 'auto'
         wb.calculation.fullCalcOnLoad = True
+        wb.calculation.fullPrecision = True
 
         # Save the workbook with variables updated
         print("Saving workbook with updated variables...")
@@ -407,6 +409,7 @@ def update_excel_variables(excel_path):
         print("Ensuring formulas are marked for recalculation...")
         wb.calculation.calcMode = 'auto'
         wb.calculation.fullCalcOnLoad = True
+        wb.calculation.fullPrecision = True
 
         # Save the workbook with updated variables and hidden sheets
         print("Saving workbook with all updates...")