Refactor config cache API: auto expiration, tests added

Update provider API docs and add serialization section

Refactor ConfigR provider API and update docs/examples

Remove JsonSerializerOptions docs and clean up examples

Merge branch 'main' of https://github.com/mbanagouro/configr

Add configurable cache duration to ConfigR

Update best-practices.md

Merge branch 'main' of https://github.com/mbanagouro/configr

Improve security guidelines and fix encoding issues

Fix formatting in security README document

Improve README structure, clarity, and accessibility

Optimize key formatting with Span, stackalloc, ArrayPool

Security hardening: input validation, docs, tests

Update MySQL test password in CI/CD config

Update MySQL root password in ci-cd.yml