Phase 4 routing decisions depend on knowing whether the SLM classifier
is actually firing or whether the heuristic is silently doing all the
work. Adds the instrumentation to make that observable.
router.ClassifierSource enum (heuristic / slm / slm_fallback) is set
on Task by every classifier:
- HeuristicClassifier → ClassifierHeuristic
- slm.Classifier → ClassifierSLM on success, ClassifierSLMFallback when
the SLM call fails or returns unparseable output
The source is plumbed through router.Outcome to QualityTracker, which
now maintains per-source counters alongside the existing per-arm × task
EMA scores. QualitySnapshot serializes both (classifier_counts is
omitempty for back-compat with pre-feature quality.json files).
lazyClassifier logs at INFO the first time it falls back to heuristic
because the SLM hasn't booted yet — distinguishes operational fallback
from an unconfigured-SLM run.
slm.Manager.Start() now records elapsed-to-healthy and the main.go
goroutine logs it as part of the "SLM ready" event. Confirms whether
short-lived runs are racing the boot cycle.
New `gnoma router stats` subcommand prints both tables (arm × task
quality, classifier source breakdown) from quality.json with a Phase 4
trust hint when the data is too sparse or the SLM share is low.
6 new tests cover ClassifierSource string/enum, heuristic + SLM source
propagation, QualityTracker counter round-trip, and back-compat
restore from a legacy quality.json without classifier_counts.
- 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.
vikingowl