fix: mpg_cluster Read uses list instead of status to find by name

`flyctl mpg status <name>` doesn't work — it requires the cluster ID.
Switch Read and post-create read-back to use `flyctl mpg list` and
find the cluster by name, matching the pattern used by postgres_cluster.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: joshpollara

internal/resources/mpg_cluster_resource.go

@@ -160,14 +160,17 @@ func (r *mpgClusterResource) Create(ctx context.Context, req resource.CreateRequ
 		return
 	}
 
-	var result flyctlMPGCluster
-	err = r.flyctl.RunJSON(ctx, &result, "mpg", "status", plan.Name.ValueString())
+	cluster, err := r.findClusterByName(ctx, plan.Name.ValueString())
 	if err != nil {
 		resp.Diagnostics.AddError("Error reading MPG cluster after creation", err.Error())
 		return
 	}
+	if cluster == nil {
+		resp.Diagnostics.AddError("Error finding MPG cluster after creation", "Cluster was created but not found in the list")
+		return
+	}
 
-	r.setModelFromAPI(&plan, &result)
+	r.setModelFromAPI(&plan, cluster)
 	resp.Diagnostics.Append(resp.State.Set(ctx, &plan)...)
 }
 
@@ -178,18 +181,17 @@ func (r *mpgClusterResource) Read(ctx context.Context, req resource.ReadRequest,
 		return
 	}
 
-	var result flyctlMPGCluster
-	err := r.flyctl.RunJSON(ctx, &result, "mpg", "status", state.Name.ValueString())
+	cluster, err := r.findClusterByName(ctx, state.Name.ValueString())
 	if err != nil {
-		if flyctl.IsNotFound(err) {
-			resp.State.RemoveResource(ctx)
-			return
-		}
 		resp.Diagnostics.AddError("Error reading MPG cluster", err.Error())
 		return
 	}
+	if cluster == nil {
+		resp.State.RemoveResource(ctx)
+		return
+	}
 
-	r.setModelFromAPI(&state, &result)
+	r.setModelFromAPI(&state, cluster)
 	resp.Diagnostics.Append(resp.State.Set(ctx, &state)...)
 }
 
@@ -219,6 +221,20 @@ func (r *mpgClusterResource) ImportState(ctx context.Context, req resource.Impor
 	resource.ImportStatePassthroughID(ctx, path.Root("name"), req, resp)
 }
 
+func (r *mpgClusterResource) findClusterByName(ctx context.Context, name string) (*flyctlMPGCluster, error) {
+	var results []flyctlMPGCluster
+	err := r.flyctl.RunJSON(ctx, &results, "mpg", "list")
+	if err != nil {
+		return nil, err
+	}
+	for i := range results {
+		if results[i].Name == name {
+			return &results[i], nil
+		}
+	}
+	return nil, nil
+}
+
 func (r *mpgClusterResource) setModelFromAPI(model *models.MPGClusterResourceModel, api *flyctlMPGCluster) {
 	id := api.ID
 	if id == "" {

internal/resources/mpg_cluster_resource_mock_test.go

@@ -11,8 +11,8 @@ func TestMPGClusterResource_lifecycle(t *testing.T) {
 		"mpg create --name test-pg --org personal --region iad": {
 			Stdout: "Created MPG cluster test-pg\n",
 		},
-		"mpg status test-pg --json": {
-			Stdout: `{"id":"mpg-123","name":"test-pg","status":"running","primary_region":"iad","region":"iad","plan":"starter","volume_size":10,"pg_major_version":16,"enable_postgis":false}`,
+		"mpg list --json": {
+			Stdout: `[{"id":"mpg-123","name":"test-pg","status":"running","primary_region":"iad","region":"iad","plan":"starter","volume_size":10,"pg_major_version":16,"enable_postgis":false}]`,
 		},
 		"mpg destroy test-pg --yes": {
 			Stdout: "Destroyed test-pg\n",