Refactor code structure for improved readability and maintainability

tests/test_data_records.py

@@ -0,0 +1,19 @@
+"""Tests for src/pygui/backend/data_records.py."""
+from pygui.backend.data_records import read_data_records
+
+
+def test_reads_rows_after_data_marker(tmp_path):
+    p = tmp_path / "s.csv"
+    p.write_text(
+        "Wafer ID=A12\n"
+        "Label,1,2\nX (mm),0,10\nY (mm),10,-10\n"
+        "data\n"
+        "0.0,149.0,148.5\n"
+        "0.5,149.2,148.4\n",
+        encoding="utf-8",
+    )
+    recs = read_data_records(str(p))
+    assert len(recs) == 2
+    assert recs[0].time == 0.0
+    assert recs[0].values == [149.0, 148.5]
+    assert recs[1].values == [149.2, 148.4]