Removes the USP_* stored procedures for Auth, Location, and Brewery
data access in favour of services built with Dapper.
Adds a new Features.Locations slice and optimistic concurrency support
for the Brewery slice.
Same pattern as the Breweries migration: Service.UserManagement and the
UserAccount repository fold into Features.UserManagement, with MediatR
queries replacing UserService. UpdateUserCommand/Handler carry forward
IUserService.UpdateAsync as-is (it has no HTTP route today, and adding one
is a separate decision from this migration). Adds handler/repository test
coverage that didn't exist before, since Service.UserManagement had no
test project.
