refactor(cli): add required input-dir argument

Author: S1M0N38

src/balatrobench/cli.py

@@ -25,6 +25,7 @@ def create_parser() -> argparse.ArgumentParser:
     parser.add_argument(
         "--input-dir",
         type=Path,
+        required=True,
         help="Input directory with run data (e.g., runs/v1.0.0)",
     )
     parser.add_argument(
@@ -65,10 +66,6 @@ def main() -> None:
     args = parser.parse_args()
 
     # Determine input directory
-    if not args.input_dir:
-        print("Error: --input-dir is required")
-        sys.exit(1)
-
     input_dir = args.input_dir.resolve()
 
     if not input_dir.exists():

tests/balatrobench/unit/test_cli.py

@@ -164,9 +164,9 @@ def test_create_parser(self) -> None:
         # Check parser metadata
         assert parser.prog == "balatrobench"
 
-        # Parse with no arguments to check defaults
-        args = parser.parse_args([])
-        assert args.input_dir is None
+        # Parse with required argument to check defaults
+        args = parser.parse_args(["--input-dir", "/some/path"])
+        assert args.input_dir == Path("/some/path")
         assert args.output_dir == Path("site/benchmarks")
         assert args.version is None
         assert args.webp is False
@@ -217,9 +217,9 @@ def test_main_requires_input_dir(
         with pytest.raises(SystemExit) as exc_info:
             main()
 
-        assert exc_info.value.code == 1
+        assert exc_info.value.code == 2
         captured = capsys.readouterr()
-        assert "Error: --input-dir is required" in captured.out
+        assert "required" in captured.err
 
     def test_main_exits_when_input_dir_not_found(
         self,