map: implement seeded generation; allow passing custom seed

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I742b7e59c7ca872539d4ebfe3a03b44f6a6a6964

src/map.c

@@ -170,9 +170,6 @@ void get_random_floor_tile(Map *map, int *x, int *y, int attempts) {
 }
 
 void dungeon_generate(Dungeon *d, Map *map, int floor_num) {
-  // Seed RNG with floor number for deterministic generation
-  rng_seed(floor_num * 12345);
-
   // Initialize map to all walls
   map_init(map);