Stage 5 of the candle-native pivot. Adds first-class support for
auto-loading a configured set of models when the neuron service
activates.
Config:
- NeuronConfig.default_models: Vec<ModelSpec> (defaults to []).
- neuron.example.toml ships a commented [[default_models]] example.
Activation flow (crates/neuron/src/startup.rs::load_default_models):
- Sequential — VRAM contention makes parallel loads risky.
- Per-entry timing logged at info level on success.
- Failures logged as warnings; the next entry is still attempted.
- An empty list short-circuits without log noise.
Called from main.rs after the registry is built and before the axum
listener binds, so /models reflects the loaded state from the very
first request.
data/neuron.service gains TimeoutStartSec=1800s. With activation
blocked on potentially slow first-time HF downloads + GGUF
materialisation, systemd's default 90s would kill larger model loads
mid-flight.
Two non-gated tests in tests/activation.rs cover the
continues-past-failure and empty-list paths using a synthetically
unknown harness name to fail loads fast without touching the network.
The cuda-integration test from earlier stages still exercises the
real load/unload lifecycle.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>