fix: address PR review follow-ups

changes/300-transparent-hover-background.md

@@ -0,0 +1,4 @@
+type: fixed
+area: config
+
+- Accepted `subtitleStyle.hoverBackground` as an alias for `subtitleStyle.hoverTokenBackgroundColor`, so setting it to `transparent` removes hover token backgrounds.

changes/301-managed-playback-exit.md

@@ -0,0 +1,4 @@
+type: fixed
+area: launcher
+
+- Launcher-managed playback now exits the background SubMiner app when the video closes, while explicit background launches stay persistent.