Only PUT /api/config took the span lock; model.set, moa, custom-endpoint
create/activate/delete, memory-provider saves, and the profile-dir model
write ran load→mutate→save unlocked in worker threads. The desktop fires
these concurrently with its debounced autosave — whichever save landed
second silently dropped the other's mutation (#88913/#89184 lost-write
flavor). Race test with slowed save proves both writes now survive.
Teknium
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