Add composition metric col support

Author: munrojm

src/atomscale/timeseries/rheed.py

@@ -41,8 +41,13 @@ class RHEEDProvider(TimeseriesProvider[RHEEDVideoResult]):
         "first_order_fwhm_1": "First Order FWHM",
         "lattice_spacing": "Lattice Spacing",
         "tar_metric": "TAR Metric",
+        "composition_metric": "Composition Metric",
     }
-    DROP_IF_ALL_NA: Sequence[str] = ["reconstruction_intensity", "tar_metric"]
+    DROP_IF_ALL_NA: Sequence[str] = [
+        "reconstruction_intensity",
+        "tar_metric",
+        "composition_metric",
+    ]
     INDEX_COLS: Sequence[str] = ["Angle", "Frame Number"]
 
     def fetch_raw(self, client: BaseClient, data_id: str, **kwargs) -> Any:

tests/test_rheed_video.py

@@ -22,6 +22,7 @@ def result(client: Client):
 
 
 def test_get_dataframe(result: RHEEDVideoResult):
+    # Core columns that should always be present
     column_names = set(
         [
             "Strain",
@@ -38,9 +39,12 @@ def test_get_dataframe(result: RHEEDVideoResult):
             "Half Order Intensity R",
             "Specular FWHM",
             "First Order FWHM",
-            "Time",
             "UNIX Timestamp",
             "Relative Time",
+            # Optional columns (included if data exists)
+            "Time",
+            "TAR Metric",
+            "Composition Metric",
         ]
     )