Both are process-lifetime per-path structures with the same growth shape as the caches
this PR already bounds: _workspace_cache only cleared on service shutdown, the
(server_id, file_path) dedup bucket never. Each resets past a fixed cap (512); for the
stat cache that costs a few re-stats, for the dedup bucket one re-fired INFO line per
key, and a single clear() keeps the lock-free stat cache thread-safe.
1c21a50254