Bulk bike assignment now updates each activity's profile too.
Fixes
Assigning several activities to a different bike at once now re-applies profiles per activity, using the same order as everywhere else: an activity-type match first, then the bike's default profile. Previously the activities kept the profile from their old bike, which could lead to the wrong components tracking wear.
Removing a bike from activities in bulk now clears their profiles as well.
This also gives you a quick way to fix profiles across many activities: select them and re-assign the same bike, and each activity picks up the right profile again.