Static topic mapping may select a stale epoch when the epoch delta overflows

### Description

Static topic mapping sorts long epoch values by subtracting them and narrowing the result to int. When two epochs differ by more than Integer.MAX_VALUE, the comparator can reverse their order. In replacement mode, checkAndBuildMappingItems then keeps the stale broker mapping instead of the latest one.

### Expected behavior

Epochs should be ordered with Long.compare so the newest mapping always wins without arithmetic overflow.

### Reproduction

Create two mapping details for the same logical queue with epochs 0 and Long.MAX_VALUE, call checkAndBuildMappingItems with replace enabled, and observe that the epoch-0 mapping is selected.

Start at checkAndBuildMappingItems and trace the replacement-mode ordering of mapping details for the same logical queue. Reproduce the issue with epochs 0 and Long.MAX_VALUE, then verify that the latest epoch is selected without overflow and add or run a regression check for that behavior.

Written by the indexing model from the issue text.