Add scrobbling support (Last.fm + ListenBrainz) and rsp settings reload

- Full Last.fm API implementation with MD5 signing (track.updateNowPlaying, track.scrobble)
- Full ListenBrainz API implementation (/1/submit-listens for playing_now and single)
- ScrobbleState in daemon tracking track, start time, and unix timestamp per play
- Scrobble threshold: ≥30s play AND (≥half duration OR ≥4 min)
- Duration extraction from symphonia codec params into AudioMetadata and Track
- Token validation at daemon startup and on config change
- ListenBrainz token valid (user: Salmonium) command to re-read config from disk (avoids token in shell history)
- Desktop notifications for token validation results
- Empty-credential filtering (empty string = no-op)

1 files changed, 2 insertions, 0 deletions

diff --git a/tests/queue.rs b/tests/queue.rs
index a73c312..ccc6e54 100644
--- a/tests/queue.rs
+++ b/tests/queue.rs
@@ -7,6 +7,7 @@ fn track(path: &str, title: Option<&str>, artist: Option<&str>, album: Option<&s
         title: title.map(|s| s.to_string()),
         artist: artist.map(|s| s.to_string()),
         album: album.map(|s| s.to_string()),
+        duration_secs: None,
     }
 }
 
@@ -16,6 +17,7 @@ fn track_no_meta(path: &str) -> Track {
         title: None,
         artist: None,
         album: None,
+        duration_secs: None,
     }
 }