refactor: rename env.sh to setup.sh

More conventional name for development environment setup script.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: HFooladi

CLAUDE.md

@@ -10,7 +10,7 @@ Molax is a high-performance JAX framework for molecular active learning. It uses
 
 ```bash
 # Setup (using uv)
-source env.sh
+source setup.sh
 
 # Test
 pytest tests/

env.sh setup.shenv.sh renamed to setup.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 # Minimal environment setup script for molax
-# Usage: source env.sh
+# Usage: source setup.sh
 
 set -e