fix(ets): route ETS-specific functions through sandbox adapter (#37)

* fix(ets): route ETS functions through @cache_adapter for sandbox support

ETS-specific functions in the __using__ macro were calling :ets directly,
bypassing sandbox isolation. Move all calls through @cache_adapter so
the sandbox adapter is used when sandbox?: true is configured.

Add corresponding module-level functions to Cache.ETS that delegate
to :ets, matching the signatures already present in Cache.Sandbox.

* fix(sandbox): add match_element? clause for nested tuple pattern matching

Without this clause, nested tuples in sandbox data were compared with
strict equality instead of recursive pattern matching via match_pattern?.

Author: BobbieBarker