fix: media_paths NameError, import order, add error logging and tests

- Move media_paths assignment before voice message handling to prevent
  NameError at runtime
- Fix broken import layout in transcription.py (httpx/loguru after class)
- Add error logging to OpenAITranscriptionProvider matching Groq style
- Add regression tests for voice transcription and no-media fallback

Made-with: Cursor

tests/channels/test_whatsapp_channel.py

@@ -163,6 +163,54 @@ async def test_group_policy_mention_accepts_mentioned_group_message():
     assert kwargs["sender_id"] == "user"
 
 
+@pytest.mark.asyncio
+async def test_voice_message_transcription_uses_media_path():
+    """Voice messages are transcribed when media path is available."""
+    ch = WhatsAppChannel(
+        {"enabled": True, "transcriptionProvider": "openai", "transcriptionApiKey": "sk-test"},
+        MagicMock(),
+    )
+    ch._handle_message = AsyncMock()
+    ch.transcribe_audio = AsyncMock(return_value="Hello world")
+
+    await ch._handle_bridge_message(
+        json.dumps({
+            "type": "message",
+            "id": "v1",
+            "sender": "12345@s.whatsapp.net",
+            "pn": "",
+            "content": "[Voice Message]",
+            "timestamp": 1,
+            "media": ["/tmp/voice.ogg"],
+        })
+    )
+
+    ch.transcribe_audio.assert_awaited_once_with("/tmp/voice.ogg")
+    kwargs = ch._handle_message.await_args.kwargs
+    assert kwargs["content"].startswith("Hello world")
+
+
+@pytest.mark.asyncio
+async def test_voice_message_no_media_shows_not_available():
+    """Voice messages without media produce a fallback placeholder."""
+    ch = WhatsAppChannel({"enabled": True}, MagicMock())
+    ch._handle_message = AsyncMock()
+
+    await ch._handle_bridge_message(
+        json.dumps({
+            "type": "message",
+            "id": "v2",
+            "sender": "12345@s.whatsapp.net",
+            "pn": "",
+            "content": "[Voice Message]",
+            "timestamp": 1,
+        })
+    )
+
+    kwargs = ch._handle_message.await_args.kwargs
+    assert kwargs["content"] == "[Voice Message: Audio not available]"
+
+
 def test_load_or_create_bridge_token_persists_generated_secret(tmp_path):
     token_path = tmp_path / "whatsapp-auth" / "bridge-token"