Align book content with current py3plex subsystems

[Copilot]

The book had fallen behind the repository’s current architecture and newer additions. This updates the manuscript so readers can map book concepts to the active package layout and examples.

• Book architecture coverage

  • Added current subsystem landmarks for algebra, semiring, embeddings, ml/embedding, dsl/lint, dsl/program, experiments, meta, out_of_core, and optimizer.
  • Updated Appendix A’s repository map and example pointers.

• Algorithm and workflow alignment

  • Added concise coverage for embeddings, algebraic paths/closure, meta-analysis, experiment records, out-of-core execution, and planning infrastructure.
  • Added DSL workflow guidance for static linting and GraphProgram rewrites.

• Reference and validation updates

  • Expanded Appendix E with current advanced API entry points.
  • Added book integrity tests ensuring current subsystems and examples remain mentioned.
  • Added high-level repo-to-book pinning tests that require top-level py3plex/ package directories and public examples/ folders to be classified, with documented landmarks reflected in the book.
  • Updated the README stats badge expectation in version consistency tests to match current repo metadata.

[SkBlaz]

@copilot I want tests that pin repo content to book content, at least high level. New additions must be added to book, too.

[Copilot]

@copilot I want tests that pin repo content to book content, at least high level. New additions must be added to book, too.

Addressed in 2bd55b8. The book integrity tests now classify top-level py3plex/ package directories and public examples/ folders, and require documented landmarks to be mentioned in the book so future high-level additions must update the manuscript coverage.