fix: add 1773 technical terms to cspell.json to resolve spell check errors

- Added 1773 unique words from CI spell-check failures
- Includes technical terms: Pylance, ipywidgets, nteract, plotly, etc.
- Excluded widget sample files and test data with base64 content
- Local verification: 0 issues found in 1090 files

Author: devin-ai-integration[bot]