refactor: harden diagnostics and consolidate runtime code

audit/internal/webui/api_system_test.go

@@ -0,0 +1,50 @@
+package webui
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"bee/audit/internal/app"
+)
+
+func TestSystemTimeEndpointReportsEpochLocalTimeAndTimezone(t *testing.T) {
+	before := time.Now().Add(-time.Second).UnixMilli()
+	rec := httptest.NewRecorder()
+	NewHandler(HandlerOptions{}).ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/api/system/time", nil))
+	after := time.Now().Add(time.Second).UnixMilli()
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+	var body struct {
+		EpochMS   int64  `json:"epoch_ms"`
+		LocalTime string `json:"local_time"`
+		Timezone  string `json:"timezone"`
+	}
+	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+		t.Fatalf("decode response: %v", err)
+	}
+	if body.EpochMS < before || body.EpochMS > after {
+		t.Fatalf("epoch_ms = %d, want value in [%d, %d]", body.EpochMS, before, after)
+	}
+	if _, err := time.ParseInLocation("2006-01-02 15:04:05", body.LocalTime, time.Local); err != nil {
+		t.Fatalf("local_time = %q: %v", body.LocalTime, err)
+	}
+	if strings.TrimSpace(body.Timezone) == "" {
+		t.Fatal("timezone must not be empty")
+	}
+}
+
+func TestNetworkDHCPRejectsMalformedJSONBeforeChangingNetwork(t *testing.T) {
+	h := &handler{opts: HandlerOptions{App: &app.App{}}}
+	rec := httptest.NewRecorder()
+	h.handleAPINetworkDHCP(rec, httptest.NewRequest(http.MethodPost, "/api/network/dhcp", strings.NewReader("{")))
+
+	if rec.Code != http.StatusBadRequest {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusBadRequest)
+	}
+}