adding naive jax and libraries and make adjustments

engine/jax/__init__.py

@@ -0,0 +1,13 @@
+"""JAX-compatible training and environment modules for PHANTOM."""
+
+from __future__ import annotations
+
+try:
+    import jax  # noqa: F401
+    import jax.numpy as jnp  # noqa: F401
+
+    JAX_AVAILABLE = True
+except ImportError:
+    JAX_AVAILABLE = False
+
+__all__ = ["JAX_AVAILABLE"]