many improvements and prototype launcher image

shared/src/commonMain/kotlin/net/sergeych/toread/storage/LibraryStorage.kt

@@ -217,6 +217,8 @@ interface ReadingStateRepository {
     fun upsert(state: ReadingStateRecord)
     fun get(id: String): ReadingStateRecord?
     fun getForBodyCluster(bodyClusterId: String): ReadingStateRecord?
+    fun deleteForBodyCluster(bodyClusterId: String): Int
+    fun delete(id: String): Boolean
 }
 
 interface BookmarkRepository {