refactor(output): share the JSON, created-resource and batch tails

Mutations end with a.jsonResult or a.created instead of hand-rolled
--json branches, the two identical jsonResult/writeMutationJSON helpers
become one, and writeBatchJSON checks --json itself so batch commands
share one tail.

Signed-off-by: bircni <bircni@icloud.com>

internal/app/time.go

@@ -174,11 +174,8 @@ $ tea time log https://gitea.com/OWNER/REPO/issues/12 45m`, Annotations: map[str
 		if err != nil {
 			return err
 		}
-		if a.options.json != "" {
-			return a.writeJSON(cmd, item)
-		}
 		a.done(cmd, "Logged %s on %s", spent(item.Seconds), strings.TrimSuffix(refLabel(target.Repo, n, item.IssueTitle), " ()"))
-		return nil
+		return a.jsonResult(cmd, item)
 	}}
 }