Owns the per-connection retry-cache ETS table, created once at init — BEFORE the Connection that reads it starts, since it's an early child of the ConnectionSupervisor.

This is why RetryCache.ETS never creates its table lazily: the owner guarantees it exists before any reader runs, so there's no create race (and no try/rescue race guard). The table is :public so reads/writes happen directly from any process; it dies (and is recreated on restart) with this owner.

NOTE: this owns ETS because the default RetryCache adapter is ETS. A different retry-cache adapter (DETS, Redis) owns its own resources — see the adapter; the framework only provides this supervision slot for the local case.