- Changed encoding fallback order to prioritize iso-8859-1/latin-1 over cp1252
- Increased encoding test from 1KB to 10KB to catch issues deeper in files
- Added proper file handle cleanup on encoding failures
- Resolves 'charmap codec can't decode byte 0x9d' error in rolodex import
- Tested with rolodex file containing 52,100 rows successfully
- Created IMPORT_GUIDE.md: Complete user guide with step-by-step instructions
* Detailed import order for all 27+ tables
* Troubleshooting guide
* Data validation procedures
* Best practices and performance notes
- Created IMPORT_SYSTEM_SUMMARY.md: Technical implementation summary
* Complete list of all implemented functions (28 import + 7 sync)
* Architecture and data flow diagrams
* Module organization
* Testing status and next steps
* ~3,000 lines of code documented
