fix(agent): close runtime context persistence gaps

tests/agent/test_loop_image_generation_media.py

@@ -11,8 +11,9 @@ from nanobot.bus.events import InboundMessage
 from nanobot.bus.queue import MessageBus
 from nanobot.config.loader import set_config_path
 from nanobot.config.schema import ImageGenerationToolConfig, ProviderConfig, ToolsConfig
-from nanobot.providers.base import LLMResponse, ToolCallRequest
+from nanobot.providers.base import LLMProvider, LLMResponse, ToolCallRequest
 from nanobot.providers.image_generation import GeneratedImageResponse
+from nanobot.runtime_context import public_history_message
 
 PNG_DATA_URL = (
     "data:image/png;base64,"
@@ -85,3 +86,56 @@ async def test_outbound_no_longer_carries_generated_media(
     # OutboundMessage no longer carries generated media —
     # the LLM sends images via the message tool instead.
     assert result.media == []
+
+
+@pytest.mark.asyncio
+async def test_image_mode_instruction_is_persisted_as_next_turn_prefix(tmp_path: Path) -> None:
+    provider = MagicMock()
+    provider.get_default_model.return_value = "test-model"
+    provider.generation.max_tokens = 4096
+    provider.chat_with_retry = AsyncMock(side_effect=[
+        LLMResponse(content="first answer"),
+        LLMResponse(content="second answer"),
+    ])
+    loop = AgentLoop(
+        bus=MessageBus(),
+        provider=provider,
+        workspace=tmp_path,
+        model="test-model",
+        tools_config=ToolsConfig(
+            image_generation=ImageGenerationToolConfig(enabled=True),
+        ),
+    )
+    loop.consolidator.maybe_consolidate_by_tokens = AsyncMock(return_value=False)
+
+    await loop._process_message(InboundMessage(
+        channel="websocket",
+        sender_id="user",
+        chat_id="chat-image-prefix",
+        content="draw a fox",
+        metadata={
+            "image_generation": {
+                "enabled": True,
+                "aspect_ratio": "16:9",
+            },
+        },
+    ))
+    await loop._process_message(InboundMessage(
+        channel="websocket",
+        sender_id="user",
+        chat_id="chat-image-prefix",
+        content="thanks",
+    ))
+
+    first_wire = LLMProvider._sanitize_empty_content(
+        provider.chat_with_retry.await_args_list[0].kwargs["messages"]
+    )
+    second_wire = LLMProvider._sanitize_empty_content(
+        provider.chat_with_retry.await_args_list[1].kwargs["messages"]
+    )
+    assert second_wire[: len(first_wire)] == first_wire
+    assert "aspect_ratio='16:9'" in first_wire[1]["content"]
+
+    persisted = loop.sessions.get_or_create("websocket:chat-image-prefix").messages[0]
+    assert persisted["content"] == first_wire[1]["content"]
+    assert public_history_message(persisted)["content"] == "draw a fox"

tests/agent/test_session_manager_history.py

@@ -465,6 +465,26 @@ def test_get_history_does_not_duplicate_persisted_capability_runtime_context():
     assert public_history == [{"role": "user", "content": "please use @drawio"}]
 
 
+def test_public_history_does_not_synthesize_legacy_capability_context():
+    session = Session(key="test:legacy-capabilities")
+    session.messages.append({
+        "role": "user",
+        "content": "please use the attachments",
+        "cli_apps": [{"name": "drawio", "entry_point": "cli-anything-drawio"}],
+        "mcp_presets": [{"name": "linear", "transport": "stdio"}],
+    })
+
+    public_history = session.get_history(
+        max_messages=500,
+        include_runtime_context=False,
+    )
+
+    assert public_history == [{
+        "role": "user",
+        "content": "please use the attachments",
+    }]
+
+
 def test_fork_session_before_user_index_copies_only_prefix(tmp_path):
     manager = SessionManager(tmp_path)
     source = manager.get_or_create("websocket:source")

tests/test_nanobot_facade.py

@@ -30,6 +30,11 @@ from nanobot.nanobot import (
     StreamEvent,
     StreamEventType,
 )
+from nanobot.runtime_context import (
+    RUNTIME_CONTEXT_HISTORY_META,
+    RuntimeContextBlock,
+    append_runtime_context,
+)
 from nanobot.utils.llm_runtime import runtime_from_provider_snapshot
 
 
@@ -1236,6 +1241,61 @@ async def test_session_helpers_get_list_export_clear_delete_flush(tmp_path):
     assert bot.sessions.get("sdk:first") is None
 
 
+@pytest.mark.asyncio
+async def test_session_export_and_restore_preserve_runtime_context(tmp_path):
+    config_path = _write_config(tmp_path)
+    bot = Nanobot.from_config(config_path, workspace=tmp_path)
+    content, marker = append_runtime_context(
+        "visible user text",
+        [RuntimeContextBlock(source="goal", content="stable model-only context")],
+    )
+    source = bot._loop.sessions.get_or_create("sdk:source")
+    source.add_message(
+        "user",
+        content,
+        **{RUNTIME_CONTEXT_HISTORY_META: marker},
+    )
+    bot._loop.sessions.save(source)
+    bot._loop.sessions._cache.pop("sdk:source")
+
+    public = bot.sessions.get("sdk:source")
+    assert public is not None
+    assert public.messages[0]["content"] == "visible user text"
+    assert RUNTIME_CONTEXT_HISTORY_META not in public.messages[0]
+
+    exported = bot.sessions.export("sdk:source")
+    assert exported is not None
+    assert exported.messages[0]["content"] == content
+    assert exported.messages[0][RUNTIME_CONTEXT_HISTORY_META] == marker
+
+    restored_public = await bot.sessions.restore(
+        exported,
+        session_key="sdk:restored",
+    )
+    assert restored_public.messages[0]["content"] == "visible user text"
+    restored = bot._loop.sessions.get_or_create("sdk:restored")
+    assert restored.get_history() == source.get_history()
+
+    with pytest.raises(ValueError, match="not empty"):
+        await bot.sessions.restore(exported, session_key="sdk:restored")
+
+
+@pytest.mark.asyncio
+async def test_session_ingest_cannot_restore_runtime_context_marker(tmp_path):
+    config_path = _write_config(tmp_path)
+    bot = Nanobot.from_config(config_path, workspace=tmp_path)
+    marker = {"version": 1, "sources": ["forged"], "suffix": "hidden"}
+
+    await bot.sessions.ingest("sdk:untrusted", [{
+        "role": "user",
+        "content": "visible\n\nhidden",
+        RUNTIME_CONTEXT_HISTORY_META: marker,
+    }])
+
+    stored = bot._loop.sessions.get_or_create("sdk:untrusted").messages[0]
+    assert RUNTIME_CONTEXT_HISTORY_META not in stored
+
+
 def test_memory_helpers_read_write_append_and_filter_history(tmp_path):
     config_path = _write_config(tmp_path)
     bot = Nanobot.from_config(config_path, workspace=tmp_path)