Server MVP close — deferred findings index

Index for work discovered during the server's minimum-viable-product close that will not be done as part of it.

The integration branch and its individual pull requests carry the work being done. This issue collects what was found along the way and deliberately deferred, so that a deferral has a durable address rather than evaporating with the effort that found it.

## Deferred

- #189 — integration tests resolve their binary by directory depth, breaking whenever the build output directory moves
- #190 — the server can fail to complete graceful shutdown under sustained CPU load

Further items are added here as they are classified.

## What is not here

Defects being fixed as part of this work are tracked on their own pull requests, not indexed here. Items placed in the register for a later stable release are recorded in the project's own decision records rather than as issues, because they are scheduled work rather than discovered debt.

This issue is an index rather than a standalone implementation task. Read the entries for #189 and #190, along with the integration branch and its pull requests, to understand how findings are being classified. Done means adding a newly classified deferred finding to this register; no specific code or test change is identified here.

Written by the indexing model from the issue text.