fix: read beatmapset count from osu!.db instead of iterating songs folder

src-tauri/Cargo.toml

@@ -35,6 +35,7 @@ open = "5.3.3"
 discord-rich-presence = "1.1.0"
 once_cell = "1.21.3"
 futures-util = "0.3.32"
+osynic_osudb = "0.1.4"
 
 [target.'cfg(windows)'.dependencies]
 winreg = "0.55.0"