Keep multiline beat prompts intact

tests/test_dumas_h3_longvideos.py

@@ -160,6 +160,45 @@ class DumasH3LongVideosHelperTests(unittest.TestCase):
             "keyframe carry",
         )
 
+    def test_expand_beats_auto_preserves_multiline_paragraph_as_one_beat(self):
+        beats, note = self.module.expand_beats(
+            ["wardrobe: Maya = red jacket\nMaya enters the room.\nShe sits at the table."],
+            "auto",
+        )
+
+        self.assertEqual(
+            beats,
+            ["wardrobe: Maya = red jacket\nMaya enters the room.\nShe sits at the table."],
+        )
+        self.assertEqual(note, "")
+
+    def test_expand_beats_legacy_blank_line_value_falls_back_to_auto(self):
+        beats, note = self.module.expand_beats(
+            ["Maya enters the room.\nShe sits at the table."],
+            "blank line",
+        )
+
+        self.assertEqual(
+            beats,
+            ["Maya enters the room.\nShe sits at the table."],
+        )
+        self.assertEqual(note, "")
+
+    def test_expand_beats_each_line_still_splits_multiline_paragraphs(self):
+        beats, note = self.module.expand_beats(
+            ["wardrobe: Maya = red jacket\nMaya enters the room.\nseconds: 8\nShe sits at the table."],
+            "each line",
+        )
+
+        self.assertEqual(
+            beats,
+            [
+                "wardrobe: Maya = red jacket\nMaya enters the room.",
+                "seconds: 8\nShe sits at the table.",
+            ],
+        )
+        self.assertIn("beat_split 'each line' split 1 multi-line paragraph(s) into 2 beats", note)
+
     def test_timing_summary_reports_retry_and_bucket_totals(self):
         note = self.module._format_timing_note([
             {