Brakes Locked Up on 2003 Subaru Forester

Hey I have a 2003 Forester, recently noticed the front brakes locking up, especially on hot days. Completely immobilized car, to get going again I would have to wait for them to cool and/or cool them with water if pads smoking from trying to drive with brakes engaged, and tap on calipers and master cylinder to allow pads to release. Problem got worse as it got hotter out, due to job I rarely drive car and didn’t get in for service yet. Last time pads burned a whole lot and braking felt odd (less pressure and uneven like rotors were messed up or pads burned up). Took it into brake place, they had never seen before. When they inspected, discs were in bad shape with one cracked, but I don’t think that was original problem, just caused by driving with them hot. Shop at first said fluid seemed clean but I left and later they said it was contaminated but I don’t trust them. Shop solution is replace everything: calipers, pads, hoses, flush system, and replace ABS (the most expensive part I am hoping isn’t actually necessary). I don’t trust shop for several reasons including because they admitted having never seen this and seemed content to take maximum amount of money just to replace everything without knowing what actual problem was. Has anyone out there seen this before or know problem and solution?

Thanks!

Is the problem with both front wheels or possibly with one front wheel and one rear wheel?

Is your car a manual transmission or automatic?