feat(tts-plugin): complete Plugin Architecture refactor

- Normalize Pipeline public API: create_pipeline(plugin_id, *, lang_code, device)
- EngineConfig: add lang_code field per Architecture Amendment #1
- Kokoro plugin reads config.lang_code (fixes functional regression)
- Static voice catalog in PluginManifest.voices (None = dynamic/VoiceLister)
- get_voices() reads from manifest without creating Engine
- Remove dead kwargs (sample_rate, auto_download, total_steps) from SuperTonic
- Clean up unused imports and dead code in engine implementations
- Fix test expectations for VoiceLister (mock overrides)
- Add clear_preview_pipelines() for resource management

tests/contracts/test_engine_contract.py

@@ -1,106 +1,106 @@
-"""Contract tests for Engine protocol.
-
-These tests verify that Engine implementations satisfy the architectural requirements:
-- createSession() returns EngineSession
-- dispose() is idempotent
-- After dispose(), createSession() raises EngineError
-- Engine is thread-safe for createSession()
-"""
-
-import pytest
-
-from abogen.tts_plugin.engine import Engine, EngineSession
-from abogen.tts_plugin.errors import EngineError
-
-from .conftest import FakeEngine, FakeEngineSession
-
-
-class TestEngineProtocolContract:
-    """Contract tests for the Engine protocol itself."""
-
-    def test_engine_is_protocol(self) -> None:
-        assert hasattr(Engine, "__protocol_attrs__")
-
-    def test_engine_session_is_protocol(self) -> None:
-        assert hasattr(EngineSession, "__protocol_attrs__")
-
-    def test_fake_engine_satisfies_protocol(self) -> None:
-        engine = FakeEngine()
-        assert isinstance(engine, Engine)
-
-    def test_fake_session_satisfies_protocol(self) -> None:
-        session = FakeEngineSession()
-        assert isinstance(session, EngineSession)
-
-
-class TestEngineCreateSessionContract:
-    """Contract tests for Engine.createSession()."""
-
-    def test_create_session_returns_engine_session(self) -> None:
-        engine = FakeEngine()
-        session = engine.createSession()
-        assert isinstance(session, EngineSession)
-
-    def test_create_session_returns_new_instance(self) -> None:
-        engine = FakeEngine()
-        session1 = engine.createSession()
-        session2 = engine.createSession()
-        assert session1 is not session2
-
-    def test_create_session_ownership_transfers(self) -> None:
-        """Architecture spec: Ownership transfers to caller."""
-        engine = FakeEngine()
-        session = engine.createSession()
-        assert isinstance(session, EngineSession)
-
-
-class TestEngineDisposeContract:
-    """Contract tests for Engine.dispose()."""
-
-    def test_dispose_is_idempotent(self) -> None:
-        """Architecture spec: dispose() is idempotent."""
-        engine = FakeEngine()
-        engine.dispose()
-        engine.dispose()  # Should not raise
-
-    def test_dispose_never_raises(self) -> None:
-        """Architecture spec: dispose() never raises exceptions."""
-        engine = FakeEngine()
-        engine.dispose()  # Should not raise
-
-    def test_create_session_after_dispose_raises(self) -> None:
-        """Architecture spec: After dispose(), all methods except dispose() raise EngineError."""
-        engine = FakeEngine()
-        engine.dispose()
-        with pytest.raises(EngineError):
-            engine.createSession()
-
-
-class TestEngineLifecycleContract:
-    """Contract tests for Engine lifecycle."""
-
-    def test_full_lifecycle(self) -> None:
-        """Test complete engine lifecycle: create -> sessions -> dispose."""
-        engine = FakeEngine()
-
-        # Create sessions
-        session1 = engine.createSession()
-        session2 = engine.createSession()
-
-        # Use sessions
-        assert isinstance(session1, EngineSession)
-        assert isinstance(session2, EngineSession)
-
-        # Dispose sessions
-        session1.dispose()
-        session2.dispose()
-
-        # Dispose engine
-        engine.dispose()
-
-    def test_engine_disposed_session_raises(self) -> None:
-        """Architecture spec: After dispose(), all methods except dispose() raise EngineError."""
-        engine = FakeEngine()
-        engine.dispose()
-        with pytest.raises(EngineError):
-            engine.createSession()
+"""Contract tests for Engine protocol.
+
+These tests verify that Engine implementations satisfy the architectural requirements:
+- createSession() returns EngineSession
+- dispose() is idempotent
+- After dispose(), createSession() raises EngineError
+- Engine is thread-safe for createSession()
+"""
+
+import pytest
+
+from abogen.tts_plugin.engine import Engine, EngineSession
+from abogen.tts_plugin.errors import EngineError
+
+from .conftest import FakeEngine, FakeEngineSession
+
+
+class TestEngineProtocolContract:
+    """Contract tests for the Engine protocol itself."""
+
+    def test_engine_is_protocol(self) -> None:
+        assert hasattr(Engine, "__protocol_attrs__")
+
+    def test_engine_session_is_protocol(self) -> None:
+        assert hasattr(EngineSession, "__protocol_attrs__")
+
+    def test_fake_engine_satisfies_protocol(self) -> None:
+        engine = FakeEngine()
+        assert isinstance(engine, Engine)
+
+    def test_fake_session_satisfies_protocol(self) -> None:
+        session = FakeEngineSession()
+        assert isinstance(session, EngineSession)
+
+
+class TestEngineCreateSessionContract:
+    """Contract tests for Engine.createSession()."""
+
+    def test_create_session_returns_engine_session(self) -> None:
+        engine = FakeEngine()
+        session = engine.createSession()
+        assert isinstance(session, EngineSession)
+
+    def test_create_session_returns_new_instance(self) -> None:
+        engine = FakeEngine()
+        session1 = engine.createSession()
+        session2 = engine.createSession()
+        assert session1 is not session2
+
+    def test_create_session_ownership_transfers(self) -> None:
+        """Architecture spec: Ownership transfers to caller."""
+        engine = FakeEngine()
+        session = engine.createSession()
+        assert isinstance(session, EngineSession)
+
+
+class TestEngineDisposeContract:
+    """Contract tests for Engine.dispose()."""
+
+    def test_dispose_is_idempotent(self) -> None:
+        """Architecture spec: dispose() is idempotent."""
+        engine = FakeEngine()
+        engine.dispose()
+        engine.dispose()  # Should not raise
+
+    def test_dispose_never_raises(self) -> None:
+        """Architecture spec: dispose() never raises exceptions."""
+        engine = FakeEngine()
+        engine.dispose()  # Should not raise
+
+    def test_create_session_after_dispose_raises(self) -> None:
+        """Architecture spec: After dispose(), all methods except dispose() raise EngineError."""
+        engine = FakeEngine()
+        engine.dispose()
+        with pytest.raises(EngineError):
+            engine.createSession()
+
+
+class TestEngineLifecycleContract:
+    """Contract tests for Engine lifecycle."""
+
+    def test_full_lifecycle(self) -> None:
+        """Test complete engine lifecycle: create -> sessions -> dispose."""
+        engine = FakeEngine()
+
+        # Create sessions
+        session1 = engine.createSession()
+        session2 = engine.createSession()
+
+        # Use sessions
+        assert isinstance(session1, EngineSession)
+        assert isinstance(session2, EngineSession)
+
+        # Dispose sessions
+        session1.dispose()
+        session2.dispose()
+
+        # Dispose engine
+        engine.dispose()
+
+    def test_engine_disposed_session_raises(self) -> None:
+        """Architecture spec: After dispose(), all methods except dispose() raise EngineError."""
+        engine = FakeEngine()
+        engine.dispose()
+        with pytest.raises(EngineError):
+            engine.createSession()