feat(memory) add heap monitor for frontend

meshchatx/src/frontend/js/HeapMonitor.js

@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: 0BSD
+
+let intervalId = null;
+const DEFAULT_INTERVAL = 5000;
+
+function formatBytes(bytes) {
+    if (bytes < 1024) return `${bytes} B`;
+    if (bytes < 1048576) return `${(bytes / 1024).toFixed(1)} KB`;
+    return `${(bytes / 1048576).toFixed(1)} MB`;
+}
+
+function sample() {
+    const m = performance.memory;
+    if (!m) {
+        console.log(
+            "[HeapMonitor] performance.memory not available (requires Chrome with --enable-precise-memory-info)"
+        );
+        return null;
+    }
+    return {
+        heap: m.usedJSHeapSize,
+        total: m.totalJSHeapSize,
+        limit: m.jsHeapSizeLimit,
+        ts: Date.now(),
+    };
+}
+
+function log() {
+    const s = sample();
+    if (!s) return;
+    console.log(
+        `[HeapMonitor] ${formatBytes(s.heap)} used / ${formatBytes(s.total)} total / ${formatBytes(s.limit)} limit (${((s.heap / s.limit) * 100).toFixed(1)}%)`
+    );
+}
+
+export function enableHeapMonitor(intervalMs) {
+    if (!performance.memory) {
+        console.warn(
+            "[HeapMonitor] performance.memory is not available. Use Chrome and pass --enable-precise-memory-info."
+        );
+        return;
+    }
+    if (intervalId !== null) {
+        clearInterval(intervalId);
+    }
+    const ms = intervalMs && intervalMs > 0 ? intervalMs : DEFAULT_INTERVAL;
+    log();
+    intervalId = setInterval(log, ms);
+    console.log(`[HeapMonitor] enabled, sampling every ${ms}ms`);
+}
+
+export function disableHeapMonitor() {
+    if (intervalId !== null) {
+        clearInterval(intervalId);
+        intervalId = null;
+    }
+    console.log("[HeapMonitor] disabled");
+}
+
+export function heapSnapshot() {
+    const s = sample();
+    if (s) {
+        console.table(s);
+        console.log(
+            `[HeapMonitor] heap usage: ${formatBytes(s.heap)} / ${formatBytes(s.limit)} (${((s.heap / s.limit) * 100).toFixed(1)}%)`
+        );
+    }
+}
+
+// Auto-start if VITE_HEAP_MONITOR is set
+if (typeof import.meta !== "undefined" && import.meta.env && import.meta.env.VITE_HEAP_MONITOR) {
+    const interval = parseInt(import.meta.env.VITE_HEAP_MONITOR, 10);
+    enableHeapMonitor(interval > 0 ? interval : undefined);
+}
+
+// Expose on window for runtime toggle
+if (typeof window !== "undefined") {
+    window.enableHeapMonitor = enableHeapMonitor;
+    window.disableHeapMonitor = disableHeapMonitor;
+    window.heapSnapshot = heapSnapshot;
+}

meshchatx/src/frontend/main.js

@@ -13,6 +13,7 @@ import "@mdi/font/css/materialdesignicons.css";
 import "./fonts/RobotoMonoNerdFont/font.css";
 import { startCodec2ScriptsBackgroundLoad } from "./js/Codec2Loader";
 import { createApiClient } from "./js/apiClient.js";
+import "./js/HeapMonitor.js";
 
 import App from "./components/App.vue";
 import ChangelogModal from "./components/ChangelogModal.vue";