feat: persist voice samples to disk, generate VTT, cleanup after analysis

test/testutil/fake_voice_file_store.go

@@ -0,0 +1,33 @@
+package testutil
+
+import "context"
+
+type FakeVoiceFileStore struct {
+	SaveRawPath       string
+	SaveConvertedPath string
+	SaveVTTPath       string
+	SaveRawError      error
+	SaveConvertedError error
+	SaveVTTError      error
+	CleanupError      error
+	CleanupCallCount  int
+	LastCleanupID     string
+}
+
+func (f *FakeVoiceFileStore) SaveRaw(_ context.Context, _ string, _ []byte) (string, error) {
+	return f.SaveRawPath, f.SaveRawError
+}
+
+func (f *FakeVoiceFileStore) SaveConverted(_ context.Context, _ string, _ []byte) (string, error) {
+	return f.SaveConvertedPath, f.SaveConvertedError
+}
+
+func (f *FakeVoiceFileStore) SaveVTT(_ context.Context, _ string, _ string) (string, error) {
+	return f.SaveVTTPath, f.SaveVTTError
+}
+
+func (f *FakeVoiceFileStore) Cleanup(_ context.Context, sampleID string) error {
+	f.CleanupCallCount++
+	f.LastCleanupID = sampleID
+	return f.CleanupError
+}