Does neighbor have right to park at end of shared driveway in Harris county Texas?
No, assuming that it is, in fact, a shared driveway (see your deeds), neither neighbor has the right to obstruct the right of way. You can only park within your property lines; you cannot park so as to lie within the other neighbor’s property. I had the same issue with my property, but later found out the driveway wasn’t actually shared (it belonged to me!).