"who has continued to be loyal." Possible meanings are 1) Boaz remembered his obligations to Naomi as a family member or 2) Naomi is referring to Yahweh, who was acting through Boaz or 3) Yahweh has continued to be faithful to the living and the dead. (See: [[rc://en/ta/man/jit/figs-doublenegatives]])
Naomi's husband and sons were the "dead." This can be stated differently to remove the nominal adjective "the dead." Alternate translation: "the people who have already died" (See: [[rc://en/ta/man/jit/figs-nominaladj]])
A kinsman-redeemer was a close male relative who could rescue a childless widow from financial ruin by marrying her and having a child with her. He would also reacquire the land his relatives had lost due to poverty and redeem family members who had sold themselves into slavery.