4.0.0a2: Control Plane + engine god-class drain complete

Third alpha. Two big themes since 4.0.0a1:

1. PyCaret Control Plane is alive — full FastAPI backend + React UI +
   6 LLM-native AI copilots (sessions 9-21).
2. Engine Experiment class fully drained from its 3.x god-class
   (sessions 22-29). Every public verb runs natively on top of
   sklearn instead of delegating through self._legacy.*.

Combined: 254/254 tests passing.

See CHANGELOG.md for the full user-facing release notes.

PyCaret 4.0.0a1 — lean core alpha

PyCaret 4.0.0a0 — first alpha test release

Update version to 3.3.2

Signed-off-by: Antoni Baum <antoni.baum@protonmail.com>

Bump version to 3.3.1

Merge pull request #3857 from celestinoxp/support-scikit-learn-1.4

Support Scikit-learn 1.4

Bump version to 3.2.0

Signed-off-by: Antoni Baum <antoni.baum@protonmail.com>

Remove Python 3.7 specific code

Signed-off-by: Antoni Baum <antoni.baum@protonmail.com>

Merge pull request #3628 from pycaret/pin_sklearn_1.3.0_bump_version

Pin sklearn<1.3.0, bump version to 3.0.4, cleanup

Bump version to 3.0.3

Signed-off-by: Antoni Baum <antoni.baum@protonmail.com>