The store tests stored timestamps with time.Local in their fixtures and
asserted equality against returned values that the engine round-trips
through UTC. assert.Equal compares zone identity, so on UTC machines
(CI, most cloud envs) Local==UTC and the tests passed; on a developer
machine in any other timezone (here BST, UTC+1) TestService_Put,
TestService_List, TestBoltDB_InfoPost, TestBoltDB_InfoList and several
others would fail with same wall-clock numbers but mismatched zones.
Replace time.Local with time.UTC across store/comment_test.go,
store/formatter_test.go, store/service/service_test.go,
store/engine/bolt_test.go, store/engine/engine_test.go. Production code
is untouched.