chore: add .gitignore

.gitignore

@@ -0,0 +1,23 @@
+# Compiled output
+*.out
+
+# Python cache
+__pycache__/
+*.pyc
+*.pyo
+
+# Log files
+*.log
+
+# Training logs
+*.jsonl
+
+# Test binaries (but keep .nim source files)
+**/tests/test_*
+!**/tests/test_*.nim
+!**/tests/test_*.nims
+
+# User-specific dev environment
+.envrc
+devbox.json
+devbox.lock