tasks: fix race conditions

* show resources in task details
* fix task state locking
* return task object consistently

Race condition iexisted where task State, err, and processReturnValue fields
were written by consumer goroutine and read by concurrent accessors without
proper synchronization, causing torn reads and data races.

task/task.go

@@ -42,6 +42,7 @@ const (
 )
 
 // Task represents as task in a queue encapsulates process code
+// All fields are protected by List.Mutex - access task fields only while holding list.Lock()
 type Task struct {
 	output             *Output
 	detail             *Detail
@@ -51,7 +52,7 @@ type Task struct {
 	Name               string
 	ID                 int
 	State              State
-	resources          []string
+	Resources          []string
 	wgTask             *sync.WaitGroup
 }
 
@@ -64,7 +65,7 @@ func NewTask(process Process, name string, ID int, resources []string, wgTask *s
 		Name:      name,
 		ID:        ID,
 		State:     IDLE,
-		resources: resources,
+		Resources: resources,
 		wgTask:    wgTask,
 	}
 	return task