nit: rename lastUsed field to dateLastUsed; add dateAdded field

examples/llama.android/app/src/main/java/com/example/llama/revamp/data/local/dao/ModelDao.kt

@@ -28,6 +28,6 @@ interface ModelDao {
     @Delete
     suspend fun deleteModels(models: List<ModelEntity>)
 
-    @Query("UPDATE models SET lastUsed = :timestamp WHERE id = :id")
+    @Query("UPDATE models SET dateLastUsed = :timestamp WHERE id = :id")
     suspend fun updateLastUsed(id: String, timestamp: Long)
 }

examples/llama.android/app/src/main/java/com/example/llama/revamp/data/local/entity/ModelEntity.kt

@@ -18,7 +18,7 @@ data class ModelEntity(
     @field:TypeConverters(GgufMetadataConverters::class)
     val metadata: GgufMetadata,
     val dateAdded: Long,
-    val lastUsed: Long?
+    val dateLastUsed: Long?
 ) {
     fun toModelInfo() = ModelInfo(
         id = id,
@@ -26,6 +26,7 @@ data class ModelEntity(
         path = path,
         sizeInBytes = sizeInBytes,
         metadata = metadata,
-        lastUsed = lastUsed,
+        dateAdded = dateAdded,
+        dateLastUsed = this@ModelEntity.dateLastUsed,
     )
 }

examples/llama.android/app/src/main/java/com/example/llama/revamp/data/model/ModelInfo.kt

@@ -12,7 +12,8 @@ data class ModelInfo(
     val path: String,
     val sizeInBytes: Long,
     val metadata: GgufMetadata,
-    val lastUsed: Long? = null
+    val dateAdded: Long,
+    val dateLastUsed: Long? = null,
 ) {
     val formattedSize: String
         get() = formatSize(sizeInBytes)

examples/llama.android/app/src/main/java/com/example/llama/revamp/data/repository/ModelRepository.kt

@@ -204,7 +204,7 @@ class ModelRepositoryImpl @Inject constructor(
                 sizeInBytes = modelFile.length(),
                 metadata = metadata,
                 dateAdded = System.currentTimeMillis(),
-                lastUsed = null
+                dateLastUsed = null
             ).let {
                 modelDao.insertModel(it)
                 it.toModelInfo()