Add xlsx data files and output reports

- xls_reports/: 6 site inventory detail files
- xls_ip_destruction/: 6 IP destruction basket files
- accountability_combined.xlsx: final combined accountability report
- accountability_formatted.xlsx: formatted version

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -1,7 +1,4 @@
-xls_reports/
+__pycache__/
-xls_ip_destruction/
-accountability_combined.xlsx
-accountability_formatted.xlsx
 __pycache__/
 *.pyc
 .idea/