refactor!: rename prompt field to input for task creation (#19982)

Renames the `prompt` field to `input` for task creation. This matches
the naming used in the CLI and elsewhere.

cli/exp_task_create.go

@@ -181,7 +181,7 @@ func (r *RootCmd) taskCreate() *serpent.Command {
 				Name:                    taskName,
 				TemplateVersionID:       templateVersionID,
 				TemplateVersionPresetID: templateVersionPresetID,
-				Prompt:                  taskInput,
+				Input:                   taskInput,
 			})
 			if err != nil {
 				return xerrors.Errorf("create task: %w", err)

cli/exp_task_create_test.go

@@ -75,7 +75,7 @@ func TestTaskCreate(t *testing.T) {
 					return
 				}
 
-				assert.Equal(t, prompt, req.Prompt, "prompt mismatch")
+				assert.Equal(t, prompt, req.Input, "prompt mismatch")
 				assert.Equal(t, templateVersionID, req.TemplateVersionID, "template version mismatch")
 
 				if presetName == "" {