app: add catalog commands/queries (RegisterAsset, UpdateMetadata, GetTimeline, GetAsset)

crates/application/src/catalog/queries/get_asset.rs

@@ -0,0 +1,37 @@
+use std::sync::Arc;
+use domain::{
+    catalog::entities::Asset,
+    catalog::services::resolve_metadata,
+    errors::DomainError,
+    ports::{AssetRepository, AssetMetadataRepository},
+    value_objects::{StructuredData, SystemId},
+};
+
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+pub struct GetAssetQuery {
+    pub asset_id: SystemId,
+}
+
+pub struct GetAssetHandler {
+    asset_repo: Arc<dyn AssetRepository>,
+    metadata_repo: Arc<dyn AssetMetadataRepository>,
+}
+
+impl GetAssetHandler {
+    pub fn new(
+        asset_repo: Arc<dyn AssetRepository>,
+        metadata_repo: Arc<dyn AssetMetadataRepository>,
+    ) -> Self {
+        Self { asset_repo, metadata_repo }
+    }
+
+    pub async fn execute(&self, query: GetAssetQuery) -> Result<(Asset, StructuredData), DomainError> {
+        let asset = self.asset_repo.find_by_id(&query.asset_id).await?
+            .ok_or_else(|| DomainError::NotFound(format!("Asset {} not found", query.asset_id)))?;
+
+        let layers = self.metadata_repo.find_by_asset(&asset.asset_id).await?;
+        let resolved = resolve_metadata(&layers);
+
+        Ok((asset, resolved))
+    }
+}