release 0.9.4: collapse to two-file layout

Merge classify/tree/cluster/search/acquire/textmine/stats into
ezr.py with section banners. Move app demos + tests into cli.py
as eg_<name> / eg_test_<name> functions; drop pytest scaffold.

- ezr.py: pure library, 858 LOC
- cli.py: dispatcher + demos + tests, 304 LOC
- pyproject py-modules trimmed to [ezr, cli]
- README rewritten for new layout
- CHANGELOG 0.9.4 entry

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

petter tree printing; mew 'plot" CLI script

typos

working on help system}

working on help system}