test: add deterministic resilience matrix

src/audio/create-audio-controller.ts

@@ -103,8 +103,8 @@ export function createAudioController(options: AudioControllerOptions): AudioCon
     if (!graph) return;
     try {
       await graph.resume();
-    } catch {
-      if (firstStart) await fail();
+    } catch (error) {
+      if (firstStart || (error instanceof Error && error.name === 'InvalidStateError')) await fail();
       else {
         desired = 'suspended';
         resumeIntent = 'user-required';

src/audio/synth-engine.ts

@@ -1,12 +1,44 @@
 import type { AudioContextLifecycleState, AudioGraph } from '@/audio/types';
+import { isTestFault, recordTestFaultEvent } from '@/testing/fault-hooks';
+
+declare const __PORTFOLIO_TEST_BUILD__: boolean;
+const TEST_BUILD = typeof __PORTFOLIO_TEST_BUILD__ !== 'undefined' && __PORTFOLIO_TEST_BUILD__;
 
 type AudioContextFactory = () => AudioContext;
 
 export function createBrowserSynthEngine(): AudioGraph {
+  if (TEST_BUILD && isTestFault('F10-audio-start-rejection')) {
+    recordTestFaultEvent('audio-start-rejected');
+    throw new DOMException('Injected audio start rejection', 'NotAllowedError');
+  }
   const AudioContextConstructor = window.AudioContext
     ?? (window as typeof window & { webkitAudioContext?: typeof AudioContext }).webkitAudioContext;
   if (!AudioContextConstructor) throw new Error('Web Audio is unavailable');
-  return createSynthEngine(() => new AudioContextConstructor());
+  const graph = createSynthEngine(() => new AudioContextConstructor());
+  if (!TEST_BUILD) return graph;
+  let resumeCount = 0;
+  return {
+    ...graph,
+    async resume() {
+      resumeCount += 1;
+      if (isTestFault('F11-audio-resume-rejection') && resumeCount > 1) {
+        recordTestFaultEvent('audio-resume-rejected');
+        throw new DOMException('Injected audio resume rejection', 'NotAllowedError');
+      }
+      if (isTestFault('F12-audio-graph-invalid') && resumeCount > 1) {
+        recordTestFaultEvent('audio-graph-invalid');
+        throw new DOMException('Injected invalid audio graph', 'InvalidStateError');
+      }
+      await graph.resume();
+    },
+    async suspend() {
+      if (isTestFault('F13-audio-suspend-rejection')) {
+        recordTestFaultEvent('audio-suspend-rejected');
+        throw new DOMException('Injected audio suspend rejection', 'InvalidStateError');
+      }
+      await graph.suspend();
+    },
+  };
 }
 
 export function createSynthEngine(createContext: AudioContextFactory): AudioGraph {