feat(04-02): extend prototype and matrix pending state

- add saved session and last token tracking in prototype state
- add matrix load/reset pending store helpers

tests/platform/test_prototype_state.py

@@ -89,3 +89,46 @@ async def test_update_settings_supports_toggle_skill_and_setters():
     assert settings.skills["web-search"] is True
     assert settings.soul["instructions"] == "Be concise"
     assert settings.safety["social-post"] is False
+
+
+@pytest.mark.asyncio
+async def test_add_saved_session_appends_named_entries():
+    store = PrototypeStateStore()
+
+    await store.add_saved_session("usr-matrix-@alice:example.org", "alpha")
+    await store.add_saved_session("usr-matrix-@alice:example.org", "beta")
+
+    sessions = await store.list_saved_sessions("usr-matrix-@alice:example.org")
+
+    assert [session["name"] for session in sessions] == ["alpha", "beta"]
+    assert all("created_at" in session for session in sessions)
+
+
+@pytest.mark.asyncio
+async def test_list_saved_sessions_returns_copy():
+    store = PrototypeStateStore()
+
+    await store.add_saved_session("usr-matrix-@alice:example.org", "alpha")
+
+    sessions = await store.list_saved_sessions("usr-matrix-@alice:example.org")
+    sessions.append({"name": "tampered", "created_at": "never"})
+
+    stored = await store.list_saved_sessions("usr-matrix-@alice:example.org")
+
+    assert [session["name"] for session in stored] == ["alpha"]
+
+
+@pytest.mark.asyncio
+async def test_get_last_tokens_used_defaults_to_zero():
+    store = PrototypeStateStore()
+
+    assert await store.get_last_tokens_used("usr-matrix-@alice:example.org") == 0
+
+
+@pytest.mark.asyncio
+async def test_set_last_tokens_used_persists_value():
+    store = PrototypeStateStore()
+
+    await store.set_last_tokens_used("usr-matrix-@alice:example.org", 321)
+
+    assert await store.get_last_tokens_used("usr-matrix-@alice:example.org") == 321