- internal/router/classifier.go: TaskClassifier interface with
Classify(ctx, prompt, history) signature. HeuristicClassifier wraps
the existing ClassifyTask() with zero behavior change.
- engine.Config.Classifier: injectable TaskClassifier; nil defaults
to HeuristicClassifier. Engine.classify() helper handles nil + error
fallback transparently.
- loop.go: all four router.ClassifyTask() call sites replaced with
e.classify(ctx, prompt). SLMClassifier slots in without further
changes to the engine.
