fix: anchor locked marker review at start

tests/test_ui_structure.py

@@ -407,6 +407,56 @@ def test_timeline_audio_mode_lock_click_scrubs_playhead_not_region(win):
     assert got_seek and abs(got_seek[-1] - 12.0) < 0.1
 
 
+def test_timeline_lock_mode_paints_playhead_line(win):
+    from PyQt6.QtGui import QColor, QImage
+    tl = win._timeline
+    tl._duration = 20.0
+    tl._view_start = 0.0
+    tl._view_span = 20.0
+    tl.resize(400, 160)
+    tl.set_audio_mode(False)
+    tl.set_clip_span(8.0, 8.0, 3.0)
+    tl.set_cursor(4.0)
+    tl._locked = True
+    tl.set_play_position(7.0)
+
+    img = QImage(tl.size(), QImage.Format.Format_ARGB32)
+    img.fill(QColor(0, 0, 0))
+    tl.render(img)
+
+    x = int(tl._time_to_x(7.0))
+    y = tl._SCROLLBAR_H + tl._RULER_H + 24
+    px = QColor(img.pixel(x, y))
+    assert px.green() > 200
+    assert px.green() > px.red() + 80
+
+
+def test_locked_marker_click_anchors_start_and_shows_end_playhead(win, monkeypatch):
+    win._file_path = "/x/video.mp4"
+    win._timeline._duration = 60.0
+    win._spn_clip_dur.setValue(8.0)
+    win._spn_clips.setValue(1)
+    win._spn_spread.setValue(3.0)
+    win._timeline.set_clip_span(win._clip_span, win._clip_dur, win._spn_spread.value())
+    win._btn_lock.setChecked(True)
+    seeks = []
+    monkeypatch.setattr(win._mpv, "seek", lambda t: seeks.append(t))
+    monkeypatch.setattr(win._mpv, "get_duration", lambda: 60.0)
+    monkeypatch.setattr(
+        win._db,
+        "get_by_output_path",
+        lambda _path: {"clip_count": 3, "clip_duration": 6.0, "spread": 2.0},
+    )
+
+    win._on_marker_clicked(10.0, "/tmp/clip_001.mp4")
+
+    assert abs(win._cursor - 10.0) < 0.01
+    assert abs(win._timeline._cursor - 10.0) < 0.01
+    assert abs(win._timeline._clip_span - 10.0) < 0.01
+    assert abs((win._timeline._play_pos or 0.0) - 20.0) < 0.01
+    assert seeks == [20.0]
+
+
 def test_timeline_audio_mode_follows_deck(win):
     win._control_deck.setCurrentWidget(win._tab_audio)
     assert win._timeline._audio_mode is True