- Branch::users() was hasMany (users.branch_id doesn't exist), now
  belongsToMany through role_user pivot
- NotificationLog missing read_at in $fillable despite column existing
- Trainer::assignments() used wrong FK join (employee PK vs user FK),
  replaced with hasManyThrough via Employee
- POSService referenced phantom wallet.frozen_amount column
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>