fix(tests): Fix import paths and update for google-genai API

tests/test_ast_parser.py

@@ -4,7 +4,7 @@ from src.file_cache import ASTParser
 def test_ast_parser_initialization() -> None:
  """Verify that ASTParser can be initialized with a language string."""
  parser = ASTParser(language="python")
- assert parser.language == "python"
+ assert parser.language.name == "python"
 
 def test_ast_parser_parse() -> None:
  """Verify that the parse method returns a tree_sitter.Tree."""