feat: establish voice assistant V1 baseline

src/voice_assistant/tts/mock.py

@@ -0,0 +1,18 @@
+from collections.abc import AsyncIterator
+
+from .adapter import TTSAdapter
+
+
+class MockTTSAdapter(TTSAdapter):
+    def __init__(self) -> None:
+        self.calls: list[str] = []
+
+    async def synthesize(
+        self,
+        text: str,
+    ) -> AsyncIterator[bytes]:
+        self.calls.append(text)
+
+        yield b"\x01\x02\x03\x04"
+        yield b"\x05\x06\x07\x08"
+