Q-W3 review follow-ups: golden hash literal test, CLAUDE.md wav_codec bullet, dead RecordedCapture field comment, makeUniqueTag residual note

tests/test_wav_codec.cpp

@@ -9,7 +9,9 @@
 // extraction (whole / tail window / clamp / out-of-range); truncate plan (kept<all,
 // no-op keep-all, kept==0, grow rejected) with exact size-field values; patchU32LE;
 // buildFloat32Wav golden header + parse round-trip; hashBytes/hashWavContent
-// determinism, metadata-skip, fallback, and domain separation.
+// determinism, metadata-skip, fallback, and domain separation; a golden hash
+// literal pinning exact hex output for a fixed input (guards persisted
+// contentHash values against a silent feed-sequence drift).
 
 #include "../src/core/capture/wav_codec.h"
 
@@ -576,6 +578,21 @@ static void testHashMatchesBuildOutput() {
     CHECK(hashWavContent(wav) == hashWavContent(withMeta));
 }
 
+// Golden hash literal (review follow-up, Q-W3): the tests above prove format,
+// determinism, and relational properties (equal/different) of hashBytes and
+// hashWavContent, but none of them pins the actual output bytes — a feed-sequence
+// change (e.g. dropping the 'W' domain-separation prefix, or reordering the
+// fmt/data feed) would pass every test above while silently invalidating every
+// contentHash already persisted in existing projects' BankIndex JSON. This test
+// locks a fixed buildFloat32Wav input's hashes against exact hex literals
+// captured from the current implementation, so any such drift fails loudly here.
+static void testGoldenHashLiterals() {
+    const std::vector<double> pcm = {0.0, 0.5, -0.25, 1.0, -1.0, 0.125};
+    auto wav = buildFloat32Wav(2, 48000, 3, pcm);
+    CHECK(hashWavContent(wav) == "7ccf298c166a670a");
+    CHECK(hashBytes(wav.data(), wav.size()) == "68d8a193c958fd44");
+}
+
 int main() {
     testParseCanonicalStereo();
     testParseMonoAndLeadingChunk();
@@ -600,6 +617,7 @@ int main() {
     testHashWavContentListMetaSkipped();
     testHashWavContentDomainSeparationFromWholeFile();
     testHashMatchesBuildOutput();
+    testGoldenHashLiterals();
 
     if (g_fail == 0) std::printf("wav_codec: all tests passed\n");
     else             std::printf("wav_codec: %d CHECK(s) FAILED\n", g_fail);