DB saves were happening inside the generator after [DONE], causing
connection abort if any await failed. Moved to BackgroundTask.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Open WebUI requires this endpoint to discover and list available models
from OpenAI-compatible connections.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>