fix and update

apps/frontend/lib/api.ts

@@ -680,8 +680,6 @@ export function buildSystemSettingPayload(setting: Pick<SystemSetting, 'key' | '
 
 const GATEWAY_RETRY_STATUS = new Set([502, 503, 504]);
 const GATEWAY_RETRY_ATTEMPTS = 4;
-const GATEWAY_PROBE_MAX_ATTEMPTS = 48;
-const GATEWAY_PROBE_BASE_DELAY_MS = 450;
 const GATEWAY_STABLE_PROBE_INTERVAL_MS = 800;
 const GATEWAY_STABLE_MAX_ROUNDS = 18;
 const API_MAX_CONCURRENT = 6;
@@ -696,6 +694,7 @@ function sleep(ms: number): Promise<void> {
 
 let gatewayReadyResolved = false;
 let gatewayReadyPromise: Promise<void> | null = null;
+let stableGatewayPromise: Promise<void> | null = null;
 let gatewayReadyAt = 0;
 let activeApiRequests = 0;
 const apiRequestWaiters: Array<() => void> = [];
@@ -703,11 +702,13 @@ const apiRequestWaiters: Array<() => void> = [];
 export function resetApiGatewayWarmup() {
   gatewayReadyResolved = false;
   gatewayReadyPromise = null;
+  stableGatewayPromise = null;
 }
 
 export function invalidateApiGatewayReady() {
   gatewayReadyResolved = false;
   gatewayReadyAt = 0;
+  stableGatewayPromise = null;
   if (typeof window !== 'undefined') {
     window.dispatchEvent(new CustomEvent(API_NOT_READY_EVENT));
   }
@@ -745,26 +746,34 @@ export function subscribeApiNotReady(listener: () => void): () => void {
 /** Несколько подряд успешных /health через nginx — защита от «один OK, потом 502». */
 export async function waitForStableGateway(stableProbes = 3): Promise<void> {
   if (typeof window === 'undefined') return;
+  if (gatewayReadyResolved && stableProbes <= 1) return;
+  if (stableGatewayPromise) return stableGatewayPromise;
 
-  gatewayReadyResolved = false;
-  gatewayReadyAt = 0;
+  stableGatewayPromise = (async () => {
+    gatewayReadyResolved = false;
+    gatewayReadyAt = 0;
 
-  let streak = 0;
-  for (let attempt = 0; attempt < GATEWAY_STABLE_MAX_ROUNDS && streak < stableProbes; attempt += 1) {
-    if (await probeGatewayAlive()) {
-      streak += 1;
-      if (streak >= stableProbes) {
-        markApiGatewayReady();
-        return;
+    let streak = 0;
+    for (let attempt = 0; attempt < GATEWAY_STABLE_MAX_ROUNDS && streak < stableProbes; attempt += 1) {
+      if (await probeGatewayAlive()) {
+        streak += 1;
+        if (streak >= stableProbes) {
+          markApiGatewayReady();
+          return;
+        }
+        await sleep(GATEWAY_STABLE_PROBE_INTERVAL_MS);
+      } else {
+        streak = 0;
+        await sleep(Math.min(900 + attempt * 300, 2800));
       }
-      await sleep(GATEWAY_STABLE_PROBE_INTERVAL_MS);
-    } else {
-      streak = 0;
-      await sleep(Math.min(900 + attempt * 300, 2800));
     }
-  }
 
-  throw new ApiError('Сервер API временно недоступен. Попробуйте обновить страницу.', 503, 'GATEWAY_UNAVAILABLE');
+    throw new ApiError('Сервер API временно недоступен. Попробуйте обновить страницу.', 503, 'GATEWAY_UNAVAILABLE');
+  })().finally(() => {
+    stableGatewayPromise = null;
+  });
+
+  return stableGatewayPromise;
 }
 
 async function acquireApiSlot(): Promise<void> {
@@ -799,23 +808,7 @@ async function probeGatewayAlive(): Promise<boolean> {
   }
 }
 
-async function waitForGatewayAlive(): Promise<void> {
-  if (gatewayReadyResolved) return;
-
-  for (let attempt = 0; attempt < GATEWAY_PROBE_MAX_ATTEMPTS; attempt += 1) {
-    if (await probeGatewayAlive()) {
-      markApiGatewayReady();
-      return;
-    }
-    if (attempt + 1 < GATEWAY_PROBE_MAX_ATTEMPTS) {
-      await sleep(Math.min(GATEWAY_PROBE_BASE_DELAY_MS + attempt * 280, 2800));
-    }
-  }
-
-  throw new ApiError('Сервер API временно недоступен. Попробуйте обновить страницу.', 503, 'GATEWAY_UNAVAILABLE');
-}
-
-/** Один общий прогрев: все apiFetch ждут успешный /health, без раннего «fail-open». */
+/** Один общий прогрев: все apiFetch ждут стабильный /health через nginx. */
 export async function ensureApiGatewayReady(force = false): Promise<void> {
   if (typeof window === 'undefined') return;
   if (gatewayReadyResolved && !force) return;
@@ -823,9 +816,12 @@ export async function ensureApiGatewayReady(force = false): Promise<void> {
 
   if (force) {
     gatewayReadyResolved = false;
+    gatewayReadyAt = 0;
+    stableGatewayPromise = null;
   }
 
-  gatewayReadyPromise = waitForGatewayAlive().finally(() => {
+  const probes = force ? 2 : 1;
+  gatewayReadyPromise = waitForStableGateway(probes).finally(() => {
     gatewayReadyPromise = null;
   });
 
@@ -848,7 +844,7 @@ async function fetchWithGatewayRetry(url: string, init: RequestInit): Promise<Re
       if (GATEWAY_RETRY_STATUS.has(response.status) && attempt + 1 < GATEWAY_RETRY_ATTEMPTS) {
         invalidateApiGatewayReady();
         try {
-          await waitForStableGateway(2);
+          await ensureApiGatewayReady(true);
         } catch {
           await sleep(gatewayRetryDelay(attempt));
         }
@@ -860,7 +856,7 @@ async function fetchWithGatewayRetry(url: string, init: RequestInit): Promise<Re
       if (attempt + 1 < GATEWAY_RETRY_ATTEMPTS) {
         invalidateApiGatewayReady();
         try {
-          await waitForStableGateway(2);
+          await ensureApiGatewayReady(true);
         } catch {
           await sleep(gatewayRetryDelay(attempt));
         }