Benchmark service startup and persistence resource stability

## Objective

Measure configuration/build startup cost, settings load/save throughput, logging overhead, shutdown flush latency, allocations, retained memory, file handles, and repeated failure/recovery cycles. Record baseline and proposed numbers and identify defaults that are too expensive for small apps.

## Completion guidance

- Keep the implementation focused on the objective while allowing the assignee to improve the approach based on research.
- Document important decisions, rejected alternatives, dependencies, and follow-up work.
- Add or update tests and documentation appropriate to the work.
- Verify locally and in CI where the task changes code or generated artifacts.

No files, tests, or entry points are named. Begin by locating the startup, settings persistence, logging, shutdown, and failure/recovery paths, then define baseline and proposed measurements for the listed costs and resources. Document decisions and follow-up work, add appropriate tests and documentation, and verify locally and in CI.

Written by the indexing model from the issue text.