feat: add decision summary to refinement API

cmd/sdrd/decision_summary.go

@@ -0,0 +1,29 @@
+package main
+
+import "sdr-wideband-suite/internal/pipeline"
+
+type decisionSummary struct {
+	Total         int            `json:"total"`
+	RecordEnabled int            `json:"record_enabled"`
+	DecodeEnabled int            `json:"decode_enabled"`
+	Reasons       map[string]int `json:"reasons,omitempty"`
+}
+
+func summarizeDecisions(decisions []pipeline.SignalDecision) decisionSummary {
+	summary := decisionSummary{Reasons: map[string]int{}}
+	summary.Total = len(decisions)
+	for _, d := range decisions {
+		if d.ShouldRecord {
+			summary.RecordEnabled++
+		}
+		if d.ShouldAutoDecode {
+			summary.DecodeEnabled++
+		}
+		reason := d.Reason
+		if reason == "" {
+			reason = "unspecified"
+		}
+		summary.Reasons[reason]++
+	}
+	return summary
+}

cmd/sdrd/http_handlers.go

@@ -156,13 +156,14 @@ func registerAPIHandlers(mux *http.ServeMux, cfgPath string, cfgManager *runtime
 		snap := phaseSnap.Snapshot()
 		windowStats := buildWindowStats(snap.refinementInput.Windows)
 		out := map[string]any{
-			"plan":         snap.refinementInput.Plan,
-			"windows":      snap.refinementInput.Windows,
-			"window_stats": windowStats,
-			"candidates":   len(snap.refinementInput.Candidates),
-			"scheduled":    len(snap.refinementInput.Scheduled),
-			"signals":      len(snap.refinement.Signals),
-			"decisions":    len(snap.refinement.Decisions),
+			"plan":             snap.refinementInput.Plan,
+			"windows":          snap.refinementInput.Windows,
+			"window_stats":     windowStats,
+			"candidates":       len(snap.refinementInput.Candidates),
+			"scheduled":        len(snap.refinementInput.Scheduled),
+			"signals":          len(snap.refinement.Signals),
+			"decisions":        len(snap.refinement.Decisions),
+			"decision_summary": summarizeDecisions(snap.refinement.Decisions),
 		}
 		_ = json.NewEncoder(w).Encode(out)
 	})