set up chess engine env variable at startup

utils/dependencies_checker.py

@@ -25,8 +25,12 @@ def find_stockfish_path():
 
 
 def check_dependencies():
-    stockfish_path = find_stockfish_path()
-    if stockfish_path:
-        print(f"Found Stockfish at: {stockfish_path}")
+    if os.getenv("CHESS_ENGINE_PATH") is None:
+        stockfish_path = find_stockfish_path()
+        if stockfish_path:
+            print(f"Found Stockfish at: {stockfish_path}")
+            os.environ["CHESS_ENGINE_PATH"] = stockfish_path
+        else:
+            print("Stockfish not found!")
     else:
-        print("Stockfish not found!")
+        print(f"Stockfish already set to {os.getenv("CHESS_ENGINE_PATH")}")