[DEV] Support buffer overflow for Id gap fix

Rework buffer overflow to keep in mind that overflow cannot happen without real reason. In local persistence, the only case is Lost ID.

Start by tracing the local persistence buffer-overflow handling and the Lost ID path described in the issue. Determine why an overflow can occur there and define the expected behavior for that case; done means the Id gap fix handles genuine Lost ID overflow without treating unexplained overflow as normal.

Written by the indexing model from the issue text.