Opening a zone the first time built its terrain, scene objects and manifests
and ran ImageMagick on the web thread, stalling the dashboard for seconds.
- Workers: the shared pool plus Workers::Reply (answer at once when built,
else from a worker via Web::Defer).
- terrain_chunks/terrain_layers/scene/paths/scenery/flairs (world3d, property
and showcase routes) and terrain textures go through it; results are built
once in OnceCaches, the .raw is read once per zone for chunks, layers and
flairs, deflated bodies are cached thread-safely.
- ImageMagick conversions are deduplicated and written under a temporary name.
- Workers don't query the CDClient, read settings or call mongoose: ZoneTable,
render components, flairs, object names, LOT kinds and terrain texture names
are read at startup; client_location is read once; base64 is plain C++.
- Logger writes one line at a time (mutex; localtime's buffer is shared).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
