test: pin JUCE WASAPI exclusive device-type name (#90)

The shared player bundle (feedBack#824) detects exclusive-style output
by string-matching getCurrentDevice().outputType. The name is hardcoded
in vendored JUCE; a JUCE upgrade renaming it would silently disable the
feedpak-under-exclusive routing. Fail the build instead.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

tests/juce-exclusive-type-name.test.js

@@ -0,0 +1,30 @@
+// Pins the JUCE WASAPI device-type names the shared player bundle keys on.
+//
+// The renderer decides "output is exclusive-style" by string-matching
+// getCurrentDevice().outputType against 'Windows Audio (Exclusive Mode)'
+// (see feedBack/static/app.js, _isExclusiveOutputType). That name is a
+// hardcoded, unlocalised string inside the vendored JUCE. If a JUCE upgrade
+// renames it, the feedpak-under-exclusive routing silently stops engaging —
+// this test turns that into a build-time failure instead.
+
+const { test } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+
+const WASAPI_CPP = path.join(
+    __dirname, '..', 'JUCE', 'modules', 'juce_audio_devices', 'native',
+    'juce_WASAPI_windows.cpp');
+
+test('vendored JUCE still names the exclusive WASAPI type "Windows Audio (Exclusive Mode)"', () => {
+    const src = fs.readFileSync(WASAPI_CPP, 'utf8');
+    assert.ok(
+        src.includes('return "Windows Audio (Exclusive Mode)"'),
+        'JUCE WASAPI exclusive type name changed — update _isExclusiveOutputType in feedBack/static/app.js');
+    // The shared-mode low-latency type must remain distinct: the renderer
+    // predicate relies on exact equality so this name must NOT collapse into
+    // the exclusive one.
+    assert.ok(
+        src.includes('"Windows Audio (Low Latency Mode)"'),
+        'JUCE WASAPI low-latency type name changed — re-verify the exclusive predicate');
+});