- Rename milestone directory from 01_1957_perceptron to 01_1958_perceptron
- Update all references to use 1958 (publication year) for consistency
with academic citation format (rosenblatt1958perceptron)
- Changes affect: READMEs, docs, tests, milestone tracker
Rationale: Using 1958 aligns with the publication year and standard
academic citations, while 1957 was the development year.
Cherry-picked from: 28ca41582 (feature/tito-dev-validate)
- Create conclusion.md summarizing the TinyTorch journey
- Add to PDF table of contents before Appendix
- Close the "Don't import torch. Build it." theme
- Cover accomplishments, mindset shift, paths forward