- README.md / docs/architecture.md: remove the '664 opcode handlers' /
'664+ opcodes' figure (unverifiable — actual register*Handler() call
count is 33, but most opcodes are bulk-registered via array loops).
Reword to describe coverage qualitatively.
- docs/threading.md: WorldSocket::connectAsync(), startWatchdog(), and
TerrainManager::startWorkers() do not exist. Reference the actual
symbols: connect() / asyncPumpLoop(), the inline lambda in run(),
and TerrainManager::initialize() spawning workerLoop().
