fix resuming video playback after background audio only mode.

src-tauri/src/player/mod.rs

@@ -80,6 +80,22 @@ pub fn update_lockscreen_metadata(_meta: &LockscreenMetadata) -> Result<(), Stri
     }
 }
 
+/// Set the base offset (seconds) added to positions reported to the Android
+/// lockscreen scrubber. Used by the background-audio handoff: the audio stream
+/// starts at the handoff point (StartTimeTicks), so ExoPlayer's position is
+/// relative and must be shifted back to absolute to match the full duration.
+/// Pass 0.0 to clear on exit. No-op off Android.
+pub fn set_lockscreen_position_offset(_offset_seconds: f64) -> Result<(), String> {
+    #[cfg(target_os = "android")]
+    {
+        return android::set_position_offset(_offset_seconds);
+    }
+    #[cfg(not(target_os = "android"))]
+    {
+        Ok(())
+    }
+}
+
 use crate::utils::lock::MutexSafe;
 use log::{debug, error, warn};
 use std::sync::{Arc, Mutex};