docs: update Claude.md and roadmap to reflect v4.1.0 achievements

Key updates to reflect completed dependency splitting implementation:

Claude.md changes:
- Update status from 4.1.0b5 to 4.1.0 production ready
- Add lightweight architecture section with dependency splitting strategy
- Update core value proposition to highlight <2MB package size
- Add Simple API pattern with detect() and process() functions
- Update performance requirements to reflect validated 190x speedup
- Add dependency tests and package size tests to testing guidelines
- Update installation examples to showcase optional extras

roadmap.rst changes:
- Mark 4.1.0 as released with comprehensive achievement summary
- Document lightweight architecture transformation (8MB → <2MB)
- Add installation examples for different extras combinations
- Update future roadmap to focus on enhancements while maintaining core

These documentation updates reflect the major architectural milestone
achieved in dependency splitting, making DataFog a truly lightweight
library with optional functionality.

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

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

Author: sidmohan0