feat: add privacy-aware hybrid routing

tests/unit/test_chat_service_hybrid.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+import tempfile
+import unittest
+from pathlib import Path
+
+from javis.core.chat_service import ChatService
+from javis.memory.sqlite_store import SQLiteSessionStore
+from javis.providers.base import ChatMessage
+
+
+class _CompatibleHybrid:
+    name = "hybrid"
+    model = "auto"
+
+    def chat(self, messages: list[ChatMessage]) -> str:
+        return "Antwort"
+
+    def supports_session(self, provider: str, model: str) -> bool:
+        return (provider, model) in {
+            ("hybrid", "auto"),
+            ("ollama", "qwen3:8b"),
+        }
+
+
+class HybridChatServiceTests(unittest.TestCase):
+    def test_old_local_session_remains_loadable_after_hybrid_upgrade(self) -> None:
+        with tempfile.TemporaryDirectory() as temporary_directory:
+            store = SQLiteSessionStore(Path(temporary_directory) / "sessions.sqlite3")
+            old_session = store.create_session("ollama", "qwen3:8b")
+            store.append_exchange(old_session.id, "Alt", "Verlauf")
+            service = ChatService(store, _CompatibleHybrid())
+
+            loaded = service.load_session(old_session.id)
+
+        self.assertEqual([message.content for message in loaded.messages], ["Alt", "Verlauf"])
+
+
+if __name__ == "__main__":
+    unittest.main()