Davis would have fired on Sumter regardless of whether the resupply effort was escorted by warships or not. He would have order Beauregard to reduce the fort if Lincoln sent an unarmed merchant ship to Charleston with nothing but food.
Davis would not allow the status quo to continue. He knew it would be war, and he accepted that as the price to reduce Sumter.
I have already pointed out to you what the official telegraph said. They had absolutely no intention of firing on the fort if Anderson would state the time of evacuation. Beauregard was given all the discretion necessary to avoid any confrontation.
The arrival of the Ships made this impossible, because now Beauregard had been put in the position of having to fight a two front engagement, because the Ships would attack him from the coast, and the fort would attack him from the harbor.
Again, Ships caused the war. Had there been no ships, there would have been no war.
Read the telegram. See how it differs from how you are trying to characterize it. Do you need a link?