Improve attachment memory safety, downloads, and high-memory alert UX.

Stream large receives to disk with chunk acks to cap renderer RAM, evict
off-screen display blobs, and route exports through a disk-aware download
service. Fix the high-memory dialog (backdrop dismiss, copy, log actions),
allow diagnostics paths in the path jail, and restore persisted image
hydration after reload.

Co-authored-by: Cursor <cursoragent@cursor.com>

toju-app/src/app/infrastructure/diagnostics/diagnostics.bootstrap.spec.ts

@@ -0,0 +1,108 @@
+import '@angular/compiler';
+import {
+  afterEach,
+  beforeEach,
+  describe,
+  expect,
+  it,
+  vi
+} from 'vitest';
+import { EnvironmentInjector, Injector } from '@angular/core';
+
+import { PerfDiagnosticsCollector } from './diagnostics.collector';
+import {
+  bootstrapPerfDiagnostics,
+  registerImmediatePerfDiagCollector,
+  resetDiagnosticsBootstrapStateForTests
+} from './diagnostics.bootstrap';
+import type { PerfDiagEntry } from './diagnostics.models';
+
+describe('diagnostics.bootstrap', () => {
+  let injector: EnvironmentInjector;
+  let collector: {
+    collectSample: ReturnType<typeof vi.fn>;
+    buildEntries: ReturnType<typeof vi.fn>;
+  };
+
+  beforeEach(() => {
+    resetDiagnosticsBootstrapStateForTests();
+
+    collector = {
+      collectSample: vi.fn(() => ({
+        storeDomains: { attachment: 1024 },
+        storeBytes: { attachment: 1024 },
+        components: { ChatMessageItemComponent: 12 },
+        componentDomains: { chat: 12 },
+        suspectedLeaks: [],
+        heap: { usedJsHeapMb: 256, totalJsHeapMb: 300 },
+        route: '/room/test',
+        durationMs: 2
+      })),
+      buildEntries: vi.fn(() => ([
+        {
+          collectedAt: 1,
+          source: 'renderer',
+          type: 'store',
+          payload: { domains: { attachment: 1024 } }
+        },
+        {
+          collectedAt: 1,
+          source: 'renderer',
+          type: 'components',
+          payload: { domains: { chat: 12 } }
+        },
+        {
+          collectedAt: 1,
+          source: 'renderer',
+          type: 'heap',
+          payload: { usedJsHeapMb: 256 }
+        }
+      ] satisfies PerfDiagEntry[]))
+    };
+
+    injector = Injector.create({
+      providers: [{ provide: PerfDiagnosticsCollector, useValue: collector }]
+    }) as EnvironmentInjector;
+  });
+
+  afterEach(() => {
+    resetDiagnosticsBootstrapStateForTests();
+  });
+
+  it('registers immediate renderer samples without perf diagnostics being enabled', () => {
+    registerImmediatePerfDiagCollector(injector);
+
+    const entries = globalThis.__collectPerfDiagSample?.() ?? [];
+
+    expect(entries).toHaveLength(3);
+    expect(entries.find((entry) => entry.type === 'store')?.payload).toEqual({
+      domains: { attachment: 1024 }
+    });
+
+    expect(entries.find((entry) => entry.type === 'components')?.payload).toEqual({
+      domains: { chat: 12 }
+    });
+  });
+
+  it('keeps the immediate collector registered after periodic sampling stops', async () => {
+    vi.useFakeTimers();
+    vi.stubGlobal('window', { addEventListener: vi.fn() });
+
+    registerImmediatePerfDiagCollector(injector);
+
+    const reportSample = vi.fn(async () => {
+      throw new Error('writer unavailable');
+    });
+
+    await bootstrapPerfDiagnostics({
+      isPerfDiagEnabled: async () => true,
+      reportPerfDiagSample: reportSample
+    }, injector);
+
+    await vi.runOnlyPendingTimersAsync();
+
+    expect(globalThis.__collectPerfDiagSample?.()).toHaveLength(3);
+    vi.useRealTimers();
+    vi.unstubAllGlobals();
+  });
+});

toju-app/src/app/infrastructure/diagnostics/diagnostics.bootstrap.ts

@@ -16,11 +16,38 @@ const SAMPLE_INTERVAL_MS = 10_000;
 
 let started = false;
 let sampleTimer: ReturnType<typeof setInterval> | null = null;
+let immediateCollectorRegistered = false;
+
+export function registerImmediatePerfDiagCollector(injector: EnvironmentInjector): void {
+  if (immediateCollectorRegistered) {
+    return;
+  }
+
+  let immediateSampleCollector: PerfDiagnosticsCollector | null = null;
+
+  runInInjectionContext(injector, () => {
+    immediateSampleCollector = inject(PerfDiagnosticsCollector);
+  });
+
+  globalThis.__collectPerfDiagSample = () => {
+    if (!immediateSampleCollector) {
+      return [];
+    }
+
+    const sample = immediateSampleCollector.collectSample();
+
+    return sample ? immediateSampleCollector.buildEntries(sample) : [];
+  };
+
+  immediateCollectorRegistered = true;
+}
 
 export async function bootstrapPerfDiagnostics(
   api: ElectronApi,
   injector: EnvironmentInjector
 ): Promise<void> {
+  registerImmediatePerfDiagCollector(injector);
+
   const reportSample = api.reportPerfDiagSample;
 
   if (started || !api.isPerfDiagEnabled || !reportSample) {
@@ -41,22 +68,6 @@ export async function bootstrapPerfDiagnostics(
 
   started = true;
 
-  let immediateSampleCollector: PerfDiagnosticsCollector | null = null;
-
-  runInInjectionContext(injector, () => {
-    immediateSampleCollector = inject(PerfDiagnosticsCollector);
-  });
-
-  globalThis.__collectPerfDiagSample = () => {
-    if (!immediateSampleCollector) {
-      return [];
-    }
-
-    const sample = immediateSampleCollector.collectSample();
-
-    return sample ? immediateSampleCollector.buildEntries(sample) : [];
-  };
-
   const reporter: PerfDiagReporter = {
     report: (entry: PerfDiagEntry) => reportSample(entry)
   };
@@ -113,6 +124,12 @@ function stopPerfDiagnosticsSampling(): void {
     sampleTimer = null;
   }
 
-  delete globalThis.__collectPerfDiagSample;
   started = false;
 }
+
+/** @internal Resets module state between unit tests. */
+export function resetDiagnosticsBootstrapStateForTests(): void {
+  stopPerfDiagnosticsSampling();
+  immediateCollectorRegistered = false;
+  delete globalThis.__collectPerfDiagSample;
+}