added metadata parsing

tests/test_metadata.py

@@ -0,0 +1,24 @@
+from datetime import date
+from zona.models import Metadata
+from zona.builder import split_metadata
+from pathlib import Path
+
+
+def test_split_metadata(tmp_path: Path):
+    content = """---
+title: Test Post
+date: 2025-06-03
+description: This is a test.
+---
+
+# Hello World
+    """
+    test_file = tmp_path / "test.md"
+    test_file.write_text(content)
+    meta, content = split_metadata(test_file)
+
+    assert isinstance(meta, Metadata)
+    assert meta.title == "Test Post"
+    assert meta.description == "This is a test."
+    assert meta.date == date(2025, 6, 3)
+    assert content == "# Hello World"