perf(store): fast-path по ссылке, ограничение живущих всю сессию коллекций

- store.set выполнял JSON.stringify с сортировкой ключей над старым и новым
  значением каждого обновляемого ключа; ежесекундный ui-state poll дважды в
  секунду сериализовал весь payload секций даже без изменений. Дешёвая
  проверка по идентичности отсекает частый случай.
- Sets/Maps учёта задач (handled subscription/latency/component/service jobs,
  custom proxy latencies) росли всю сессию LuCI без границ; теперь они
  ограничены 500 записями через общий хелпер.
- AI-чат модалка: параллельные отправки перемешивали удаление плейсхолдера
  "печатает" и портили ветку диалога; поле ввода и кнопка блокируются на
  время запроса.

fe-app-tachyon/src/tachyon/helpers/capCollectionSize.ts

@@ -0,0 +1,28 @@
+// Session-lifetime job-tracking collections grow by one entry per backend
+// job; on a long-lived LuCI tab nothing pruned them. Cap oldest entries away
+// once a collection exceeds the limit - the backend cleans its own state, so
+// old ids never reappear.
+const DEFAULT_MAX_ENTRIES = 500;
+
+export function capSetSize<T>(set: Set<T>, max = DEFAULT_MAX_ENTRIES): void {
+  while (set.size > max) {
+    const oldest = set.values().next().value;
+    if (oldest === undefined) {
+      return;
+    }
+    set.delete(oldest);
+  }
+}
+
+export function capMapSize<K, V>(
+  map: Map<K, V>,
+  max = DEFAULT_MAX_ENTRIES,
+): void {
+  while (map.size > max) {
+    const oldest = map.keys().next().value;
+    if (oldest === undefined) {
+      return;
+    }
+    map.delete(oldest);
+  }
+}

fe-app-tachyon/src/tachyon/services/store.service.ts

@@ -48,6 +48,11 @@ export class StoreService<T extends Record<string, any>> {
     const diff: Partial<T> = {};
 
     for (const key in next) {
+      // Reference equality fast path: most poll ticks pass the same object
+      // identity or genuinely new objects; the sorted stringify below runs
+      // on every key of a multi-hundred-KB payload twice per second
+      // otherwise.
+      if (next[key] === prev[key]) continue;
       if (!jsonEqual(next[key], prev[key])) diff[key] = next[key];
     }
 

fe-app-tachyon/src/tachyon/tabs/dashboard/initController.ts

@@ -61,6 +61,7 @@ import { isActiveLuciTab } from '../../helpers/isActiveLuciTab';
 import { isTransientRpcError } from '../../helpers/isTransientRpcError';
 import { shouldShowLoadingForRestoredAction } from '../../helpers/restoredActionLoading';
 import { getServiceAvailability } from '../../helpers/serviceAvailability';
+import { capSetSize, capMapSize } from '../../helpers/capCollectionSize';
 
 const SECTIONS_REFRESH_INTERVAL_MS = 10000;
 const LATENCY_TEST_BUTTON_CLASS = 'dashboard-sections-grid-item-test-latency';
@@ -315,6 +316,7 @@ async function completeSubscriptionUpdateJob(
 
   if (jobId) {
     handledSubscriptionJobs.add(jobId);
+    capSetSize(handledSubscriptionJobs);
   }
 
   setSubscriptionUpdating(sectionName, false);
@@ -396,6 +398,7 @@ async function completeLatencyTestJob(jobId: string, sectionName: string) {
 
   if (jobId) {
     handledLatencyJobs.add(jobId);
+    capSetSize(handledLatencyJobs);
   }
 
   if (jobId) {
@@ -761,6 +764,7 @@ async function handleTestLatency(
       } else {
         customProxyLatencies.set(tag, -1);
       }
+      capMapSize(customProxyLatencies);
       setLatencyFetching(sectionName, false);
       completed = true;
       void fetchDashboardSections({ force: true });

fe-app-tachyon/src/tachyon/tabs/diagnostic/initController.ts

@@ -5,6 +5,7 @@ import {
 } from '../../../helpers';
 import { showToast } from '../../../helpers/showToast';
 import { notifyActionFailure } from '../../helpers/notifyActionFailure';
+import { capSetSize } from '../../helpers/capCollectionSize';
 import { runDnsCheck } from './checks/runDnsCheck';
 import { runSingBoxCheck } from './checks/runSingBoxCheck';
 import { runInboundsCheck } from './checks/runInboundsCheck';
@@ -322,6 +323,7 @@ async function followServiceActionState(state: Tachyon.ServiceActionState) {
     logger.error('[DIAGNOSTIC]', 'followServiceActionState failed', error);
   } finally {
     handledServiceActionJobs.add(jobId);
+    capSetSize(handledServiceActionJobs);
     setServiceActionStateLoading(state, false);
     await refreshDiagnosticServicesInfo({ force: true, allowInactive: true });
     void TachyonShellMethods.uiActionAck('service', jobId);
@@ -618,6 +620,8 @@ async function handleServiceRuntimeAction({
       await refreshDiagnosticServicesInfo({ force: true, allowInactive: true });
       if (jobId) {
         handledServiceActionJobs.add(jobId);
+        capSetSize(handledServiceActionJobs);
+    capSetSize(handledServiceActionJobs);
         void TachyonShellMethods.uiActionAck('service', jobId);
       }
       resetDiagnosticsChecks();

fe-app-tachyon/src/tachyon/tabs/diagnostic/partials/renderAiChatModal.ts

@@ -69,9 +69,16 @@ export function renderAiChatModal() {
     onClick: () => handleSend(),
   });
 
+  let sendInFlight = false;
+
   const handleSend = async (queryText?: string) => {
     const text = (queryText || chatInput.value).trim();
-    if (!text) return;
+    // A single request in flight: concurrent sends would interleave the
+    // "typing" placeholder removals and corrupt the thread.
+    if (!text || sendInFlight) return;
+    sendInFlight = true;
+    chatInput.disabled = true;
+    (sendBtn as HTMLButtonElement).disabled = true;
 
     const userMsg: ChatMessage = {
       sender: 'user',
@@ -146,6 +153,9 @@ export function renderAiChatModal() {
     }
 
     renderMessages();
+    sendInFlight = false;
+    chatInput.disabled = false;
+    (sendBtn as HTMLButtonElement).disabled = false;
   };
 
   chatInput.onkeydown = (e: KeyboardEvent) => {

fe-app-tachyon/src/tachyon/tabs/updates/initController.ts

@@ -1,6 +1,7 @@
 import { onMount, preserveScrollForPage } from '../../../helpers';
 import { TACHYON_ACTION_PROVIDERS_AVAILABILITY_EVENT } from '../../../constants';
 import { normalizeCompiledVersion } from '../../../helpers/normalizeCompiledVersion';
+import { capSetSize } from '../../helpers/capCollectionSize';
 import { showToast } from '../../../helpers/showToast';
 import {
   renderDownloadIcon24,
@@ -127,6 +128,7 @@ try {
   const savedJob = sessionStorage.getItem('tachyon_post_update_job');
   if (savedJob) {
     handledComponentJobs.add(savedJob);
+    capSetSize(handledComponentJobs);
     followedComponentJobs.add(savedJob);
     sessionStorage.removeItem('tachyon_post_update_job');
   }
@@ -660,6 +662,7 @@ async function completeComponentActionJob(
     }
 
     handledComponentJobs.add(jobId);
+    capSetSize(handledComponentJobs);
     setActionLoading(key, false);
     if (shouldNotify) {
       showToast(message, 'error');
@@ -670,6 +673,7 @@ async function completeComponentActionJob(
   }
 
   handledComponentJobs.add(jobId);
+  capSetSize(handledComponentJobs);
   await ackComponentActionJob(jobId);
   await applyCompletedComponentAction({
     key,
@@ -797,6 +801,7 @@ function handleComponentUiState(uiState: Tachyon.UiState) {
       void followComponentActionState(state);
     } else {
       handledComponentJobs.add(jobId);
+      capSetSize(handledComponentJobs);
       void ackComponentActionJob(jobId);
     }
   }