feat: close v3 governance evidence and slo metrics wiring

internal/app/route_resolve_api_test.go

@@ -3,11 +3,14 @@ package app
 import (
 	"context"
 	"net/http"
+	"net/http/httptest"
 	"net/url"
 	"path/filepath"
+	"strings"
 	"testing"
 	"time"
 
+	"sub2api-cn-relay-manager/internal/metrics"
 	"sub2api-cn-relay-manager/internal/routing"
 )
 
@@ -205,12 +208,20 @@ func TestNewActionSetResolveRouteFlow(t *testing.T) {
 	if err != nil {
 		t.Fatalf("ListRouteFailoverEvents() error = %v", err)
 	}
-	if len(failovers) != 1 {
-		t.Fatalf("ListRouteFailoverEvents() len = %d, want 1", len(failovers))
-	}
 	if failovers[0].FromRouteID != "codex2api" || failovers[0].ToRouteID != "asxs" || failovers[0].FailureCount != 2 {
 		t.Fatalf("ListRouteFailoverEvents()[0] = %+v, want codex2api -> asxs failure_count 2", failovers[0])
 	}
+
+	req := httptest.NewRequest(http.MethodGet, "/metrics", nil)
+	rr := httptest.NewRecorder()
+	metrics.Handler().ServeHTTP(rr, req)
+	body := rr.Body.String()
+	if !strings.Contains(body, "route_decisions_total") {
+		t.Fatal("metrics missing route_decisions_total after resolve flow")
+	}
+	if !strings.Contains(body, "route_failovers_total") {
+		t.Fatal("metrics missing route_failovers_total after fallback flow")
+	}
 }
 
 func TestResolveRouteHelpers(t *testing.T) {