Replace NodeConfig (static vram_mb, pinned) with NeuronEndpoint.
Hardware discovery and model pinning now come from neuron API and
models.toml catalogue respectively.
- config.rs: nodes -> neurons, add models_config path
- catalogue.rs: ModelProfile with pinned_on, ModelCatalogue
- poller.rs: poll neuron GET /models (ModelInfo format)
- router.rs: resolve inference endpoint via neuron GET /models/{id}/endpoint
- evictor.rs: call neuron POST /models/unload
- node.rs: remove vram_mb, pinned fields (come from discovery/catalogue)
- All 22 gateway tests updated to mock neuron API
- Remove MistralModelsResponse, ModelLifecycleRequest (no longer needed)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Emit cortex_requests_total, cortex_request_duration_seconds,
cortex_request_errors_total, and cortex_cold_starts_total with
model and node labels on every proxied request.
Add install_test_recorder() for testing metrics without HTTP listener.
Integration test verifies counters and histograms appear after proxy.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
