fix(audio): implement get_callback_state in TestBackend

- Add missing get_callback_state() override
- Returns dummy values (0.0, 0 samples) for test backend
- Fixes abstract class error in test_audio_backend.cc

1 files changed, 6 insertions, 0 deletions

diff --git a/src/tests/audio/test_audio_backend.cc b/src/tests/audio/test_audio_backend.cc
index 6a748aa..3ea6765 100644
--- a/src/tests/audio/test_audio_backend.cc
+++ b/src/tests/audio/test_audio_backend.cc
@@ -43,6 +43,12 @@ class TestBackend : public AudioBackend {
     return 0.5f;
   }
 
+  void get_callback_state(double* out_time, int64_t* out_samples) override {
+    // Test backend: return dummy state
+    *out_time = 0.0;
+    *out_samples = 0;
+  }
+
   void on_voice_triggered(float timestamp, int spectrogram_id, float volume,
                           float pan) override {
     events.push_back({timestamp, spectrogram_id, volume, pan});