Pre-public hygiene: drop dead field, ignore config.json, silence errcheck

.gitignore

@@ -1,4 +1,5 @@
 /epmon
 epmon.db*
 config.yaml
+config.json
 data/

internal/prober/prober_test.go

@@ -29,7 +29,7 @@ func svc(url string) config.Service {
 
 func TestProbeUp(t *testing.T) {
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-		w.Write([]byte("hello world"))
+		_, _ = w.Write([]byte("hello world"))
 	}))
 	defer srv.Close()
 
@@ -47,7 +47,7 @@ func TestProbeUp(t *testing.T) {
 func TestProbeDownCases(t *testing.T) {
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.URL.Path == "/missing-body" {
-			w.Write([]byte("nope"))
+			_, _ = w.Write([]byte("nope"))
 			return
 		}
 		w.WriteHeader(500)

internal/scheduler/scheduler_threshold_test.go

@@ -19,9 +19,8 @@ type thresholdObservation struct {
 
 // thresholdObserver captures every ObserveProbe call in order.
 type thresholdObserver struct {
-	mu   sync.Mutex
-	obs  []thresholdObservation
-	seen int
+	mu  sync.Mutex
+	obs []thresholdObservation
 }
 
 func (o *thresholdObserver) ObserveCheck(string, bool, int64) {}

internal/store/sqlite/sqlite.go

@@ -115,7 +115,7 @@ func (s *Store) SyncServices(ctx context.Context, services []store.ServiceMeta,
 	if err != nil {
 		return err
 	}
-	defer tx.Rollback()
+	defer func() { _ = tx.Rollback() }()
 	for _, svc := range services {
 		if _, err := tx.ExecContext(ctx,
 			`INSERT INTO services(id, name, url, updated_at) VALUES(?,?,?,?)