feat(web): report page views via sendBeacon and show stats on system page

reaction_board/web/static/api.js

@@ -57,3 +57,27 @@ export async function session() {
   const payload = await response.json();
   return payload?.data ?? payload;
 }
+
+export async function stats(params) {
+  return api("/api/stats", params);
+}
+
+export function visit(path) {
+  // 访问统计埋点：优先 sendBeacon（不阻塞导航），失败时用 keepalive fetch 兜底。
+  const body = JSON.stringify({ path });
+  try {
+    if (typeof navigator !== "undefined" && typeof navigator.sendBeacon === "function") {
+      const blob = new Blob([body], { type: "application/json" });
+      if (navigator.sendBeacon("/api/visit", blob)) return;
+    }
+  } catch {
+    // 忽略，走 fetch 兜底
+  }
+  fetch("/api/visit", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body,
+    credentials: "same-origin",
+    keepalive: true,
+  }).catch(() => {});
+}