Various test fixes

vibe_bot/tests/test_tts.py

@@ -8,6 +8,10 @@ import numpy as np
 import pytest
 
 
+class ChunkProcessingError(Exception):
+    """Simulates a chunk processing failure in the fake Kokoro processor."""
+
+
 def test_tts_engine_init(mock_kokoro_tts: MagicMock) -> None:
     """Test TTSEngine initialization."""
     from vibe_bot.tts import TTSEngine
@@ -91,7 +95,7 @@ def test_generate_audio_chunk_failure(mock_kokoro_tts: MagicMock) -> None:
         lang: str,
     ) -> tuple[np.ndarray, int]:
         if chunk == "bad chunk":
-            raise Exception("processing error")
+            raise ChunkProcessingError("processing error")
         return np.array([0.1, 0.2], dtype=np.float32), 24000
 
     mock_kokoro_tts["chunk_text"].return_value = [