Fix wrong session index + save file corruption

Signed-off-by: AnErrupTion <anerruption@disroot.org>

src/config/SavedUsers.zig

@@ -5,6 +5,8 @@ const SavedUsers = @This();
 const User = struct {
     username: []const u8,
     session_index: usize,
+    first_run: bool,
+    allocated_username: bool,
 };
 
 user_list: std.ArrayList(User),
@@ -18,5 +20,9 @@ pub fn init() SavedUsers {
 }
 
 pub fn deinit(self: *SavedUsers, allocator: std.mem.Allocator) void {
+    for (self.user_list.items) |user| {
+        if (user.allocated_username) allocator.free(user.username);
+    }
+
     self.user_list.deinit(allocator);
 }