Фронтенд: стабильность прокси и рендера

- main.py: таймаут прокси 150с (холодная загрузка бэкенда до ~2мин), /healthz, чистый список маршрутов
- app.js: таймаут fetch (AbortController), защита от гонок при переключении вкладок (requestSeq)
- style.css: стили chипа ошибки кэша (multi-line заметки уже поддерживались)

src/frontend/static/app.js

@@ -19,6 +19,8 @@ const PARITY_CLASS = { ч: "badge badge-ch", з: "badge badge-zn" };
 
 let currentParity = null;
 let mode = "groups";
+let requestSeq = 0;
+const FETCH_TIMEOUT_MS = 30000;
 
 function todayName() {
   return RUSSIAN_DAYS[new Date().getDay()];
@@ -29,7 +31,16 @@ function enc(value) {
 }
 
 async function fetchJSON(url) {
-  const resp = await fetch(url);
+  const controller = new AbortController();
+  const timer = setTimeout(() => controller.abort(), FETCH_TIMEOUT_MS);
+  let resp;
+  try {
+    resp = await fetch(url, { signal: controller.signal });
+  } catch (err) {
+    throw new Error(err.name === "AbortError" ? "Время запроса истекло" : err.message);
+  } finally {
+    clearTimeout(timer);
+  }
   if (!resp.ok) {
     let detail = resp.statusText;
     try {
@@ -44,7 +55,7 @@ async function fetchJSON(url) {
 async function loadWeek() {
   try {
     const data = await fetchJSON("/api/week");
-    currentParity = data.parity;
+    if (data) currentParity = data.parity;
   } catch (_) {}
 }
 
@@ -104,32 +115,37 @@ async function setMode(next) {
   await renderView();
 }
 
-async function renderView(force = false) {
+async function renderView() {
   const value = groupSelect.value;
   if (!value) return;
   localStorage.setItem(MODES[mode].valueKey, value);
+  const seq = ++requestSeq;
   scheduleEl.innerHTML = "";
   errorEl.classList.add("hidden");
   loadingEl.classList.remove("hidden");
   try {
+    let data, status;
     if (mode === "groups") {
-      const [data, status] = await Promise.all([
-        fetchJSON(`/api/schedule/${enc(value)}${force ? "?force=1" : ""}`),
+      [data, status] = await Promise.all([
+        fetchJSON(`/api/schedule/${enc(value)}`),
         loadStatus(),
       ]);
+      if (seq !== requestSeq) return;
       renderGroupSchedule(data, status);
     } else {
-      const [data, status] = await Promise.all([
+      [data, status] = await Promise.all([
         fetchJSON(`/api/teacher/${enc(value)}`),
         loadStatus(),
       ]);
+      if (seq !== requestSeq) return;
       renderTeacher(data, status);
     }
   } catch (err) {
+    if (seq !== requestSeq) return;
     errorEl.textContent = "Ошибка: " + err.message;
     errorEl.classList.remove("hidden");
   } finally {
-    loadingEl.classList.add("hidden");
+    if (seq === requestSeq) loadingEl.classList.add("hidden");
   }
 }
 
@@ -157,6 +173,11 @@ function statusRowHTML(status) {
     const synced = formatDT(status.last_updated);
     if (modified) row.appendChild(statusChip("Изменение таблицы", modified));
     if (synced) row.appendChild(statusChip("Синхронизация", synced));
+    if (status.error) {
+      const chip = statusChip("Ошибка", status.error);
+      chip.classList.add("error");
+      row.appendChild(chip);
+    }
   }
   if (currentParity) {
     const chip = document.createElement("div");
@@ -371,11 +392,14 @@ const FREE_WEEKDAYS = ["понедельник", "вторник", "среда",
 
 async function renderRoomsView(day) {
   const chosenDay = FREE_WEEKDAYS.includes(day) ? day : (FREE_WEEKDAYS.includes(todayName()) ? todayName() : "понедельник");
+  const seq = ++requestSeq;
   scheduleEl.innerHTML = "";
   errorEl.classList.add("hidden");
   loadingEl.classList.remove("hidden");
   try {
     const status = await loadStatus();
+    const data = await fetchJSON(`/api/rooms-day?day=${enc(chosenDay)}`);
+    if (seq !== requestSeq) return;
     scheduleEl.appendChild(Object.assign(document.createElement("div"), {
       className: "schedule-title",
       textContent: "Занятость аудиторий",
@@ -386,14 +410,13 @@ async function renderRoomsView(day) {
     const wrap = document.createElement("div");
     wrap.className = "rooms-wrap";
     scheduleEl.appendChild(wrap);
-
-    const data = await fetchJSON(`/api/rooms-day?day=${enc(chosenDay)}`);
     wrap.appendChild(roomsDayTable(data));
   } catch (err) {
+    if (seq !== requestSeq) return;
     errorEl.textContent = "Ошибка: " + err.message;
     errorEl.classList.remove("hidden");
   } finally {
-    loadingEl.classList.add("hidden");
+    if (seq === requestSeq) loadingEl.classList.add("hidden");
   }
 }