The backend logged 200 OK for polls the client had already timed out on.
is_running() waited 2s for an Ollama that ships OFF (now 0.5s), is_available()
spawned 'ollama --version' every call and that command blocks ~5s when Ollama is
wedged (now cached), and both ran synchronously inside an async def, stalling the
event loop on every poll while the UI polls continuously (now to_thread).
Measured with Ollama's port blackholed: /status 5.89s -> 0.64s, concurrent GET /
stalled -> 0.06s. Poll timeout in nexus_window.py raised 2s -> 5s for margin.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>