feat(110): statistics summary

Phase 110 complete:
- add Statistics -> Podsumowanie page
- add monthly order count and value charts per integration plus total
- use Chart.js with table fallback and 04-2026 default history start
- update PAUL and DOCS technical documentation

resources/scss/app.scss

@@ -1219,6 +1219,74 @@ h4.section-title {
   }
 }
 
+.statistics-summary-page {
+  padding: 10px;
+}
+
+.statistics-summary-section {
+  display: grid;
+  gap: 12px;
+}
+
+.statistics-summary-chart-grid,
+.statistics-summary-table-grid {
+  display: grid;
+  gap: 12px;
+}
+
+@media (min-width: 1100px) {
+  .statistics-summary-chart-grid,
+  .statistics-summary-table-grid {
+    grid-template-columns: repeat(2, minmax(0, 1fr));
+    align-items: start;
+  }
+}
+
+.statistics-summary-card {
+  padding: 10px;
+}
+
+.statistics-summary-card__head {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 10px;
+  margin-bottom: 8px;
+}
+
+.statistics-summary-chart {
+  position: relative;
+  height: 320px;
+}
+
+.statistics-summary-chart canvas {
+  display: block;
+  width: 100%;
+  height: 100%;
+  border: 1px solid #e2e8f0;
+  border-radius: 6px;
+  background: #ffffff;
+}
+
+.statistics-summary-fallback {
+  margin-top: 0;
+}
+
+.statistics-summary-table {
+  min-width: 640px;
+
+  th,
+  td {
+    white-space: nowrap;
+    text-align: right;
+  }
+
+  th:first-child,
+  td:first-child {
+    text-align: left;
+  }
+}
+
 .orders-head {
   display: flex;
   align-items: flex-start;