feat(mode): Jev solo/conspiracy/split classification on nest requests (#22)

jev.go

@@ -155,6 +155,64 @@ func deref(f *float64) float64 {
 	return *f
 }
 
+// modeQuestions classifies how a request should be taken up (Epic C). The
+// escape option "other" keeps Jev from forcing a wrong class; mode is discrete,
+// so choice, not score (JEV_STRATEGIES.md strategy 3).
+var modeQuestions = map[string]any{
+	"mode": map[string]any{
+		"type":         "choice",
+		"instructions": "How should this chatroom request be taken up?",
+		"criteria": map[string]string{
+			"solo":       "Simple: one crow answers it directly.",
+			"conspiracy": "A judgment call worth several distinct readings: several crows take the same request from their different strengths.",
+			"split":      "Large with distinct parts: separate subtasks, one owner each.",
+			"other":      "None of these fits well.",
+		},
+	},
+}
+
+// ClassifyMode returns the mode when Jev is set and its choice is at or above
+// the band. "other" reads as unsure (not ok) so callers fall back to a header.
+func (j *JevClient) ClassifyMode(ctx context.Context, text string) (string, map[string]float64, bool) {
+	if j == nil {
+		return "", nil, false
+	}
+	answers, _, _, err := j.SystemOne(ctx, text, modeQuestions)
+	if err != nil {
+		return "", nil, false
+	}
+	a := answers["mode"]
+	if a.Choice == "" || a.Choice == "other" || a.Confidence == nil || *a.Confidence < j.threshold {
+		return "", nil, false
+	}
+	return a.Choice, a.Probabilities, true
+}
+
+// ClassifyMode classifies a request under the same guardrails as any call:
+// flock cap, timeout and flight log, with the probabilities recorded. Returns
+// the mode and ok; below-band or absent Jev means not ok.
+func (f *Flock) ClassifyMode(ctx context.Context, text string, budgets ...*Budget) (string, bool) {
+	if f.jev == nil {
+		return "", false
+	}
+	for _, b := range budgets {
+		if err := b.Check(); err != nil {
+			return "", false
+		}
+	}
+	f.sem <- struct{}{}
+	defer func() { <-f.sem }()
+	cctx, cancel := context.WithTimeout(ctx, f.g.CrowTimeout)
+	defer cancel()
+	start := time.Now()
+	mode, probs, ok := f.jev.ClassifyMode(cctx, text)
+	e := Event{Kind: "mode", Item: text, Crow: "Sentry", Model: f.jev.model, Ms: time.Since(start).Milliseconds(), Prob: probs, Mode: mode}
+	if f.log != nil {
+		f.log.Write(e)
+	}
+	return mode, ok
+}
+
 func (c JevCall) confident(threshold float64) bool {
 	return c.ModeConf >= threshold && c.TaskTypeConf >= threshold
 }