feat: add update_meta to SongRepositoryPort and PATCH /songs/{id}

crates/api/src/routes/songs.rs

@@ -48,12 +48,36 @@ pub async fn list_songs(
         .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, Json(ErrorResponse { error: e.to_string() })))
 }
 
+#[derive(serde::Deserialize)]
+pub struct UpdateSongRequest {
+    pub title: Option<String>,
+    pub artist: Option<String>,
+    pub original_key: Option<String>,
+}
+
 pub async fn update_song(
-    State(_state): State<Arc<AppState>>,
-    Path(_id): Path<String>,
-    Json(_body): Json<serde_json::Value>,
-) -> StatusCode {
-    StatusCode::NOT_IMPLEMENTED
+    State(state): State<Arc<AppState>>,
+    Path(id): Path<String>,
+    Json(body): Json<UpdateSongRequest>,
+) -> Result<Json<domain::SongSummary>, (StatusCode, Json<ErrorResponse>)> {
+    let uuid = Uuid::parse_str(&id).map_err(|_| {
+        (StatusCode::BAD_REQUEST, Json(ErrorResponse { error: "Invalid ID".into() }))
+    })?;
+
+    state.songs
+        .update_meta(
+            uuid,
+            body.title.as_deref(),
+            body.artist.as_deref(),
+            body.original_key.as_deref(),
+        )
+        .await
+        .map(Json)
+        .map_err(|e| match e {
+            domain::RepositoryError::NotFound =>
+                (StatusCode::NOT_FOUND, Json(ErrorResponse { error: "Not found".into() })),
+            e => (StatusCode::INTERNAL_SERVER_ERROR, Json(ErrorResponse { error: e.to_string() })),
+        })
 }
 
 pub async fn get_song(