feat(ui): draw pane frames, page keys and a scroll thumb

beefy_player/theme.tcss

@@ -76,9 +76,6 @@ StationList {
     color: ansi_default;
     width: 1fr;
     height: 1fr;
-    border: round ansi_bright_black;
-    border-title-color: ansi_default;
-    padding: 0 1;
     background: ansi_default;
 }
 
@@ -87,9 +84,6 @@ SchedulePanel {
     width: 1fr;
     height: 1fr;
     display: none;
-    border: round ansi_bright_black;
-    border-title-color: ansi_default;
-    padding: 0 1;
     background: ansi_default;
 }
 
@@ -97,8 +91,30 @@ StagePanel {
     color: ansi_default;
     layout: vertical;
     width: 1fr;
-    border: round ansi_bright_black;
-    border-title-color: ansi_default;
+    background: ansi_default;
+}
+
+#stage_frame_top,
+#stage_frame_bottom {
+    height: 1;
+    background: ansi_default;
+}
+
+#stage_middle {
+    height: 1fr;
+    background: ansi_default;
+}
+
+#stage_frame_left,
+#stage_frame_right {
+    width: 1;
+    height: 1fr;
+    background: ansi_default;
+}
+
+#stage_body {
+    width: 1fr;
+    height: 1fr;
     padding: 0 1;
     background: ansi_default;
 }
@@ -143,9 +159,6 @@ SpectrumPanel {
     color: ansi_default;
     height: 2fr;
     min-height: 6;
-    border: round ansi_bright_black;
-    border-title-color: ansi_default;
-    padding: 0 1;
     background: ansi_default;
 }