Add stability hardening and self-heal recovery

audit/internal/webui/server_test.go

@@ -34,6 +34,23 @@ func TestChartLegendNumber(t *testing.T) {
 	}
 }
 
+func TestRecoverMiddlewareReturns500OnPanic(t *testing.T) {
+	handler := recoverMiddleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		panic("boom")
+	}))
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/panic", nil)
+
+	handler.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusInternalServerError {
+		t.Fatalf("status=%d want %d", rec.Code, http.StatusInternalServerError)
+	}
+	if !strings.Contains(rec.Body.String(), "internal server error") {
+		t.Fatalf("body=%q", rec.Body.String())
+	}
+}
+
 func TestChartDataFromSamplesUsesFullHistory(t *testing.T) {
 	samples := []platform.LiveMetricSample{
 		{