fix: add verification and playback safeguards

tests/test_stream_server_baseline.py

@@ -0,0 +1,61 @@
+import json
+from pathlib import Path
+from types import SimpleNamespace
+
+import stream_server
+
+
+def make_args(**overrides):
+    values = {
+        "video": "video.mp4",
+        "playlist": None,
+        "folder": None,
+        "mode": 1,
+        "vol": 1,
+        "pixel": False,
+        "cols": None,
+        "rows": 0,
+    }
+    values.update(overrides)
+    return SimpleNamespace(**values)
+
+
+def test_calc_auto_rows_preserves_video_aspect_for_text_and_pixel():
+    text_rows = stream_server.calc_auto_rows(240, 1920, 1080, pixel_mode=False)
+    pixel_rows = stream_server.calc_auto_rows(450, 1920, 1080, pixel_mode=True)
+
+    assert text_rows == round(240 / (1920 / 1080) / 2)
+    assert pixel_rows == round(450 / (1920 / 1080))
+    assert pixel_rows > text_rows
+
+
+def test_load_folder_includes_only_supported_video_files(tmp_path):
+    for name in ["intro.mp4", "clip.MOV", "notes.txt", "image.png", "scene.webm"]:
+        (tmp_path / name).write_text("", encoding="utf-8")
+
+    items = stream_server.load_folder(str(tmp_path), default_mode=3, default_vol=2)
+
+    names = {Path(item["video"]).name for item in items}
+    assert names == {"intro.mp4", "clip.MOV", "scene.webm"}
+    assert {item["mode"] for item in items} == {3}
+    assert {item["vol"] for item in items} == {2}
+
+
+def test_build_queue_fills_playlist_defaults(tmp_path):
+    playlist = tmp_path / "playlist.json"
+    playlist.write_text(json.dumps([{"video": "clip.mp4"}]), encoding="utf-8")
+
+    queue = stream_server.build_queue(
+        make_args(playlist=str(playlist), mode=3, vol=2, pixel=False, cols=220)
+    )
+
+    assert queue == [
+        {
+            "video": "clip.mp4",
+            "mode": 3,
+            "vol": 2,
+            "pixel": False,
+            "cols": 220,
+            "rows": 0,
+        }
+    ]