fix(player-controls): reset recording feedback on handoff

docs/architecture/player-controls-contract.md

@@ -127,6 +127,10 @@ is rendered; state such as `canSeek`, `canPreviousEpisode`, and
 
 Adapters translate engine types into this model. The controls component must not
 import Video.js, hls.js, ArtPlayer, libmpv, Electron IPC, or native-view types.
+Recording state may expose a `transitionKey` that identifies its current
+playback/session owner. When that key changes, shared feedback adopts the new
+active baseline without flashing a start or saved transition from the previous
+owner.
 
 ### Commands
 
@@ -214,6 +218,11 @@ a modal/backdrop overlay is active, so transport, seek, volume, and fullscreen
 actions cannot leak through it. Escape keeps the shared component's generic
 popover-dismissal behavior.
 
+Frame-copy recording transitions use the adapter's playback/session identity as
+their `transitionKey`. Session disposal, retry, channel changes, and engine
+handoff therefore clear stale recording ownership without showing a false
+`RECORDING_SAVED` confirmation.
+
 ### Timeline scrubbing
 
 Timeline input is previewed locally while the user drags. The slider value,