Integrate Bifrost LLM gateway, add test suite, implement memory pipeline

- Add Bifrost (maximhq/bifrost) as LLM gateway: all inference routes through
  bifrost:8080/v1 with retry logic and observability; VRAMManager keeps direct
  Ollama access for VRAM flush/prewarm operations
- Switch medium model from qwen3:4b to qwen2.5:1.5b (direct call, no tools)
  via _DirectModel wrapper; complex keeps create_deep_agent with qwen3:8b
- Implement out-of-agent memory pipeline: _retrieve_memories pre-fetches
  relevant context (injected into all tiers), _store_memory runs as background
  task after each reply writing to openmemory/Qdrant
- Add tests/unit/ with 133 tests covering router, channels, vram_manager,
  agent helpers; move integration test to tests/integration/
- Add bifrost-config.json with GPU Ollama (qwen2.5:0.5b/1.5b, qwen3:4b/8b,
  gemma3:4b) and CPU Ollama providers
- Integration test 28/29 pass (only grammy fails — no TELEGRAM_BOT_TOKEN)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/unit/conftest.py

@@ -0,0 +1,80 @@
+"""
+Stub out all third-party packages that Adolf's source modules import.
+This lets the unit tests run without a virtualenv or Docker environment.
+Stubs are installed into sys.modules before any test file is collected.
+"""
+
+import sys
+from unittest.mock import MagicMock
+
+
+# ── helpers ────────────────────────────────────────────────────────────────────
+
+def _mock(name: str) -> MagicMock:
+    m = MagicMock(name=name)
+    sys.modules[name] = m
+    return m
+
+
+# ── pydantic: BaseModel must be a real class so `class Foo(BaseModel)` works ──
+
+class _FakeBaseModel:
+    model_fields: dict = {}
+
+    def __init_subclass__(cls, **kwargs):
+        pass
+
+    def __init__(self, **data):
+        for k, v in data.items():
+            setattr(self, k, v)
+
+
+_pydantic = _mock("pydantic")
+_pydantic.BaseModel = _FakeBaseModel
+
+# ── httpx: used by channels.py, vram_manager.py, agent.py ────────────────────
+
+_mock("httpx")
+
+# ── fastapi ───────────────────────────────────────────────────────────────────
+
+_fastapi = _mock("fastapi")
+_mock("fastapi.responses")
+
+# ── langchain stack ───────────────────────────────────────────────────────────
+
+_mock("langchain_openai")
+
+_lc_core = _mock("langchain_core")
+_lc_msgs = _mock("langchain_core.messages")
+_mock("langchain_core.tools")
+
+# Provide real-ish message classes so router.py can instantiate them
+class _FakeMsg:
+    def __init__(self, content=""):
+        self.content = content
+
+class SystemMessage(_FakeMsg):
+    pass
+
+class HumanMessage(_FakeMsg):
+    pass
+
+class AIMessage(_FakeMsg):
+    def __init__(self, content="", tool_calls=None):
+        super().__init__(content)
+        self.tool_calls = tool_calls or []
+
+_lc_msgs.SystemMessage = SystemMessage
+_lc_msgs.HumanMessage = HumanMessage
+_lc_msgs.AIMessage = AIMessage
+
+_mock("langchain_mcp_adapters")
+_mock("langchain_mcp_adapters.client")
+_mock("langchain_community")
+_mock("langchain_community.utilities")
+
+# ── deepagents (agent_factory.py) ─────────────────────────────────────────────
+
+_mock("deepagents")
+

tests/unit/test_agent_helpers.py

@@ -0,0 +1,161 @@
+"""
+Unit tests for agent.py helper functions:
+  - _strip_think(text)
+  - _extract_final_text(result)
+
+agent.py has heavy FastAPI/LangChain imports; conftest.py stubs them out so
+these pure functions can be imported and tested in isolation.
+"""
+
+import pytest
+
+# conftest.py has already installed all stubs into sys.modules.
+# The FastAPI app is instantiated at module level in agent.py —
+# with the mocked fastapi, that just creates a MagicMock() object
+# and the route decorators are no-ops.
+from agent import _strip_think, _extract_final_text
+
+
+# ── _strip_think ───────────────────────────────────────────────────────────────
+
+class TestStripThink:
+    def test_removes_single_think_block(self):
+        text = "<think>internal reasoning</think>Final answer."
+        assert _strip_think(text) == "Final answer."
+
+    def test_removes_multiline_think_block(self):
+        text = "<think>\nLine one.\nLine two.\n</think>\nResult here."
+        assert _strip_think(text) == "Result here."
+
+    def test_no_think_block_unchanged(self):
+        text = "This is a plain answer with no think block."
+        assert _strip_think(text) == text
+
+    def test_removes_multiple_think_blocks(self):
+        text = "<think>step 1</think>middle<think>step 2</think>end"
+        assert _strip_think(text) == "middleend"
+
+    def test_strips_surrounding_whitespace(self):
+        text = "  <think>stuff</think>  answer  "
+        assert _strip_think(text) == "answer"
+
+    def test_empty_think_block(self):
+        text = "<think></think>Hello."
+        assert _strip_think(text) == "Hello."
+
+    def test_empty_string(self):
+        assert _strip_think("") == ""
+
+    def test_only_think_block_returns_empty(self):
+        text = "<think>nothing useful</think>"
+        assert _strip_think(text) == ""
+
+    def test_think_block_with_nested_tags(self):
+        text = "<think>I should use <b>bold</b> here</think>Done."
+        assert _strip_think(text) == "Done."
+
+    def test_preserves_markdown(self):
+        text = "<think>plan</think>## Report\n\n- Point one\n- Point two"
+        result = _strip_think(text)
+        assert result == "## Report\n\n- Point one\n- Point two"
+
+
+# ── _extract_final_text ────────────────────────────────────────────────────────
+
+class TestExtractFinalText:
+    def _ai_msg(self, content: str, tool_calls=None):
+        """Create a minimal AIMessage-like object."""
+        class AIMessage:
+            pass
+        m = AIMessage()
+        m.content = content
+        m.tool_calls = tool_calls or []
+        return m
+
+    def _human_msg(self, content: str):
+        class HumanMessage:
+            pass
+        m = HumanMessage()
+        m.content = content
+        return m
+
+    def test_returns_last_ai_message_content(self):
+        result = {
+            "messages": [
+                self._human_msg("what is 2+2"),
+                self._ai_msg("The answer is 4."),
+            ]
+        }
+        assert _extract_final_text(result) == "The answer is 4."
+
+    def test_returns_last_of_multiple_ai_messages(self):
+        result = {
+            "messages": [
+                self._ai_msg("First response."),
+                self._human_msg("follow-up"),
+                self._ai_msg("Final response."),
+            ]
+        }
+        assert _extract_final_text(result) == "Final response."
+
+    def test_skips_empty_ai_messages(self):
+        result = {
+            "messages": [
+                self._ai_msg("Real answer."),
+                self._ai_msg(""),  # empty — should be skipped
+            ]
+        }
+        assert _extract_final_text(result) == "Real answer."
+
+    def test_strips_think_tags_from_ai_message(self):
+        result = {
+            "messages": [
+                self._ai_msg("<think>reasoning here</think>Clean reply."),
+            ]
+        }
+        assert _extract_final_text(result) == "Clean reply."
+
+    def test_falls_back_to_output_field(self):
+        result = {
+            "messages": [],
+            "output": "Fallback output.",
+        }
+        assert _extract_final_text(result) == "Fallback output."
+
+    def test_strips_think_from_output_field(self):
+        result = {
+            "messages": [],
+            "output": "<think>thoughts</think>Actual output.",
+        }
+        assert _extract_final_text(result) == "Actual output."
+
+    def test_returns_none_when_no_content(self):
+        result = {"messages": []}
+        assert _extract_final_text(result) is None
+
+    def test_returns_none_when_no_messages_and_no_output(self):
+        result = {"messages": [], "output": ""}
+        # output is falsy → returns None
+        assert _extract_final_text(result) is None
+
+    def test_skips_non_ai_messages(self):
+        result = {
+            "messages": [
+                self._human_msg("user question"),
+            ]
+        }
+        assert _extract_final_text(result) is None
+
+    def test_handles_ai_message_with_tool_calls_but_no_content(self):
+        """AIMessage that only has tool_calls (no content) should be skipped."""
+        msg = self._ai_msg("", tool_calls=[{"name": "web_search", "args": {}}])
+        result = {"messages": [msg]}
+        assert _extract_final_text(result) is None
+
+    def test_multiline_think_stripped_correctly(self):
+        result = {
+            "messages": [
+                self._ai_msg("<think>\nLong\nreasoning\nblock\n</think>\n## Report\n\nSome content."),
+            ]
+        }
+        assert _extract_final_text(result) == "## Report\n\nSome content."

tests/unit/test_channels.py

@@ -0,0 +1,125 @@
+"""Unit tests for channels.py — register, deliver, pending_replies queue."""
+
+import asyncio
+import pytest
+from unittest.mock import AsyncMock, patch
+
+import channels
+
+
+@pytest.fixture(autouse=True)
+def reset_channels_state():
+    """Clear module-level state before and after every test."""
+    channels._callbacks.clear()
+    channels.pending_replies.clear()
+    yield
+    channels._callbacks.clear()
+    channels.pending_replies.clear()
+
+
+# ── register ───────────────────────────────────────────────────────────────────
+
+class TestRegister:
+    def test_register_stores_callback(self):
+        cb = AsyncMock()
+        channels.register("test_channel", cb)
+        assert channels._callbacks["test_channel"] is cb
+
+    def test_register_overwrites_existing(self):
+        cb1 = AsyncMock()
+        cb2 = AsyncMock()
+        channels.register("ch", cb1)
+        channels.register("ch", cb2)
+        assert channels._callbacks["ch"] is cb2
+
+    def test_register_multiple_channels(self):
+        cb_a = AsyncMock()
+        cb_b = AsyncMock()
+        channels.register("a", cb_a)
+        channels.register("b", cb_b)
+        assert channels._callbacks["a"] is cb_a
+        assert channels._callbacks["b"] is cb_b
+
+
+# ── deliver ────────────────────────────────────────────────────────────────────
+
+class TestDeliver:
+    async def test_deliver_enqueues_reply(self):
+        channels.register("cli", AsyncMock())
+        await channels.deliver("cli-alvis", "cli", "hello world")
+        q = channels.pending_replies["cli-alvis"]
+        assert not q.empty()
+        assert await q.get() == "hello world"
+
+    async def test_deliver_calls_channel_callback(self):
+        cb = AsyncMock()
+        channels.register("telegram", cb)
+        await channels.deliver("tg-123", "telegram", "reply text")
+        cb.assert_awaited_once_with("tg-123", "reply text")
+
+    async def test_deliver_unknown_channel_still_enqueues(self):
+        """No registered callback for channel → reply still goes to the queue."""
+        await channels.deliver("cli-bob", "nonexistent", "fallback reply")
+        q = channels.pending_replies["cli-bob"]
+        assert await q.get() == "fallback reply"
+
+    async def test_deliver_unknown_channel_does_not_raise(self):
+        """Missing callback must not raise an exception."""
+        await channels.deliver("cli-x", "ghost_channel", "msg")
+
+    async def test_deliver_creates_queue_if_absent(self):
+        channels.register("cli", AsyncMock())
+        assert "cli-new" not in channels.pending_replies
+        await channels.deliver("cli-new", "cli", "hi")
+        assert "cli-new" in channels.pending_replies
+
+    async def test_deliver_reuses_existing_queue(self):
+        """Second deliver to the same session appends to the same queue."""
+        channels.register("cli", AsyncMock())
+        await channels.deliver("cli-alvis", "cli", "first")
+        await channels.deliver("cli-alvis", "cli", "second")
+        q = channels.pending_replies["cli-alvis"]
+        assert await q.get() == "first"
+        assert await q.get() == "second"
+
+    async def test_deliver_telegram_sends_to_callback(self):
+        sent = []
+
+        async def fake_tg(session_id, text):
+            sent.append((session_id, text))
+
+        channels.register("telegram", fake_tg)
+        await channels.deliver("tg-999", "telegram", "test message")
+        assert sent == [("tg-999", "test message")]
+
+
+# ── register_defaults ──────────────────────────────────────────────────────────
+
+class TestRegisterDefaults:
+    def test_registers_telegram_and_cli(self):
+        channels.register_defaults()
+        assert "telegram" in channels._callbacks
+        assert "cli" in channels._callbacks
+
+    async def test_cli_callback_is_noop(self):
+        """CLI send callback does nothing (replies are handled via SSE queue)."""
+        channels.register_defaults()
+        cb = channels._callbacks["cli"]
+        # Should not raise and should return None
+        result = await cb("cli-alvis", "some reply")
+        assert result is None
+
+    async def test_telegram_callback_chunks_long_messages(self):
+        """Telegram callback splits messages > 4000 chars into chunks."""
+        channels.register_defaults()
+        cb = channels._callbacks["telegram"]
+        long_text = "x" * 9000  # > 4000 chars → should produce 3 chunks
+        with patch("channels.httpx.AsyncClient") as mock_client_cls:
+            mock_client = AsyncMock()
+            mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+            mock_client.__aexit__ = AsyncMock(return_value=False)
+            mock_client.post = AsyncMock()
+            mock_client_cls.return_value = mock_client
+            await cb("tg-123", long_text)
+            # 9000 chars / 4000 per chunk = 3 POST calls
+            assert mock_client.post.await_count == 3

tests/unit/test_router.py

@@ -0,0 +1,200 @@
+"""Unit tests for router.py — Router, _parse_tier, _format_history, _LIGHT_PATTERNS."""
+
+import pytest
+from unittest.mock import AsyncMock, MagicMock, patch
+
+from router import Router, _parse_tier, _format_history, _LIGHT_PATTERNS
+
+
+# ── _LIGHT_PATTERNS regex ──────────────────────────────────────────────────────
+
+class TestLightPatterns:
+    @pytest.mark.parametrize("text", [
+        "hi", "Hi", "HI",
+        "hello", "hey", "yo", "sup",
+        "good morning", "good evening", "good night", "good afternoon",
+        "bye", "goodbye", "see you", "cya", "later", "ttyl",
+        "thanks", "thank you", "thx", "ty",
+        "ok", "okay", "k", "cool", "great", "awesome", "perfect",
+        "sounds good", "got it", "nice", "sure",
+        "how are you", "how are you?", "how are you doing today?",
+        "what's up",
+        "what day comes after Monday?",
+        "what day follows Friday?",
+        "what comes after summer?",
+        "what does NASA stand for?",
+        "what does AI stand for?",
+        # with trailing punctuation
+        "hi!", "hello.", "thanks!",
+    ])
+    def test_matches(self, text):
+        assert _LIGHT_PATTERNS.match(text.strip()), f"Expected light match for: {text!r}"
+
+    @pytest.mark.parametrize("text", [
+        "what is the capital of France",
+        "tell me about bitcoin",
+        "what is 2+2",
+        "write me a poem",
+        "search for news about the election",
+        "what did we talk about last time",
+        "what is my name",
+        "/think compare these frameworks",
+        "how do I install Python",
+        "explain machine learning",
+        "",  # empty string doesn't match the pattern
+    ])
+    def test_no_match(self, text):
+        assert not _LIGHT_PATTERNS.match(text.strip()), f"Expected NO light match for: {text!r}"
+
+
+# ── _parse_tier ────────────────────────────────────────────────────────────────
+
+class TestParseTier:
+    @pytest.mark.parametrize("raw,expected", [
+        ("light", "light"),
+        ("Light", "light"),
+        ("LIGHT\n", "light"),
+        ("medium", "medium"),
+        ("Medium.", "medium"),
+        ("complex", "complex"),
+        ("Complex!", "complex"),
+        # descriptive words → light
+        ("simplefact", "light"),
+        ("trivial question", "light"),
+        ("basic", "light"),
+        ("easy answer", "light"),
+        ("general knowledge", "light"),
+        # unknown → medium
+        ("unknown_category", "medium"),
+        ("", "medium"),
+        ("I don't know", "medium"),
+        # complex only if 'complex' appears in first 60 chars
+        ("this is a complex query requiring search", "complex"),
+        # _parse_tier checks "complex" before "medium", so complex wins even if medium appears first
+        ("medium complexity, not complex", "complex"),
+    ])
+    def test_parse_tier(self, raw, expected):
+        assert _parse_tier(raw) == expected
+
+
+# ── _format_history ────────────────────────────────────────────────────────────
+
+class TestFormatHistory:
+    def test_empty(self):
+        assert _format_history([]) == "(none)"
+
+    def test_single_user_message(self):
+        history = [{"role": "user", "content": "hello there"}]
+        result = _format_history(history)
+        assert "user: hello there" in result
+
+    def test_multiple_turns(self):
+        history = [
+            {"role": "user", "content": "What is Python?"},
+            {"role": "assistant", "content": "Python is a programming language."},
+        ]
+        result = _format_history(history)
+        assert "user: What is Python?" in result
+        assert "assistant: Python is a programming language." in result
+
+    def test_truncates_long_content(self):
+        long_content = "x" * 300
+        history = [{"role": "user", "content": long_content}]
+        result = _format_history(history)
+        # content is truncated to 200 chars in _format_history
+        assert len(result) < 250
+
+    def test_missing_keys_handled(self):
+        # Should not raise — uses .get() with defaults
+        history = [{"role": "user"}]  # no content key
+        result = _format_history(history)
+        assert "user:" in result
+
+
+# ── Router.route() ─────────────────────────────────────────────────────────────
+
+class TestRouterRoute:
+    def _make_router(self, classify_response: str, reply_response: str = "Sure!") -> Router:
+        """Return a Router with a mock model that returns given classification and reply."""
+        model = MagicMock()
+        classify_msg = MagicMock()
+        classify_msg.content = classify_response
+        reply_msg = MagicMock()
+        reply_msg.content = reply_response
+        # First ainvoke call → classification; second → reply
+        model.ainvoke = AsyncMock(side_effect=[classify_msg, reply_msg])
+        return Router(model=model)
+
+    async def test_force_complex_bypasses_classification(self):
+        router = self._make_router("medium")
+        tier, reply = await router.route("some question", [], force_complex=True)
+        assert tier == "complex"
+        assert reply is None
+        # Model should NOT have been called
+        router.model.ainvoke.assert_not_called()
+
+    async def test_regex_light_skips_llm_classification(self):
+        # Regex match bypasses classification entirely; the only ainvoke call is the reply.
+        model = MagicMock()
+        reply_msg = MagicMock()
+        reply_msg.content = "I'm doing great!"
+        model.ainvoke = AsyncMock(return_value=reply_msg)
+        router = Router(model=model)
+        tier, reply = await router.route("how are you", [], force_complex=False)
+        assert tier == "light"
+        assert reply == "I'm doing great!"
+        # Exactly one model call — no classification step
+        assert router.model.ainvoke.call_count == 1
+
+    async def test_llm_classifies_medium(self):
+        router = self._make_router("medium")
+        tier, reply = await router.route("what is the bitcoin price?", [], force_complex=False)
+        assert tier == "medium"
+        assert reply is None
+
+    async def test_llm_classifies_light_generates_reply(self):
+        router = self._make_router("light", "Paris is the capital of France.")
+        tier, reply = await router.route("what is the capital of France?", [], force_complex=False)
+        assert tier == "light"
+        assert reply == "Paris is the capital of France."
+
+    async def test_llm_classifies_complex_downgraded_to_medium(self):
+        # Without /think prefix, complex classification → downgraded to medium
+        router = self._make_router("complex")
+        tier, reply = await router.route("compare React and Vue", [], force_complex=False)
+        assert tier == "medium"
+        assert reply is None
+
+    async def test_llm_error_falls_back_to_medium(self):
+        model = MagicMock()
+        model.ainvoke = AsyncMock(side_effect=Exception("connection error"))
+        router = Router(model=model)
+        tier, reply = await router.route("some question", [], force_complex=False)
+        assert tier == "medium"
+        assert reply is None
+
+    async def test_light_reply_empty_falls_back_to_medium(self):
+        """If the light reply comes back empty, router returns medium instead."""
+        router = self._make_router("light", "")  # empty reply
+        tier, reply = await router.route("what is 2+2", [], force_complex=False)
+        assert tier == "medium"
+        assert reply is None
+
+    async def test_strips_think_tags_from_classification(self):
+        """Router strips <think>...</think> from model output before parsing tier."""
+        model = MagicMock()
+        classify_msg = MagicMock()
+        classify_msg.content = "<think>Hmm let me think...</think>medium"
+        reply_msg = MagicMock()
+        reply_msg.content = "I'm fine!"
+        model.ainvoke = AsyncMock(side_effect=[classify_msg, reply_msg])
+        router = Router(model=model)
+        tier, _ = await router.route("what is the news?", [], force_complex=False)
+        assert tier == "medium"
+
+    async def test_think_prefix_forces_complex(self):
+        """/think prefix is already stripped by agent.py; force_complex=True is passed."""
+        router = self._make_router("medium")
+        tier, reply = await router.route("analyse this", [], force_complex=True)
+        assert tier == "complex"
+        assert reply is None

tests/unit/test_vram_manager.py

@@ -0,0 +1,164 @@
+"""Unit tests for vram_manager.py — VRAMManager flush/poll/prewarm logic."""
+
+import asyncio
+import pytest
+from unittest.mock import AsyncMock, MagicMock, patch
+
+from vram_manager import VRAMManager
+
+
+BASE_URL = "http://localhost:11434"
+
+
+def _make_manager() -> VRAMManager:
+    return VRAMManager(base_url=BASE_URL)
+
+
+def _mock_client(get_response=None, post_response=None):
+    """Return a context-manager mock for httpx.AsyncClient."""
+    client = AsyncMock()
+    client.__aenter__ = AsyncMock(return_value=client)
+    client.__aexit__ = AsyncMock(return_value=False)
+    if get_response is not None:
+        client.get = AsyncMock(return_value=get_response)
+    if post_response is not None:
+        client.post = AsyncMock(return_value=post_response)
+    return client
+
+
+# ── _flush ─────────────────────────────────────────────────────────────────────
+
+class TestFlush:
+    async def test_sends_keep_alive_zero(self):
+        client = _mock_client(post_response=MagicMock())
+        with patch("vram_manager.httpx.AsyncClient", return_value=client):
+            mgr = _make_manager()
+            await mgr._flush("qwen3:4b")
+        client.post.assert_awaited_once()
+        _, kwargs = client.post.await_args
+        body = kwargs.get("json") or client.post.call_args[1].get("json") or client.post.call_args[0][1]
+        assert body["model"] == "qwen3:4b"
+        assert body["keep_alive"] == 0
+
+    async def test_posts_to_correct_endpoint(self):
+        client = _mock_client(post_response=MagicMock())
+        with patch("vram_manager.httpx.AsyncClient", return_value=client):
+            mgr = _make_manager()
+            await mgr._flush("qwen3:8b")
+        url = client.post.call_args[0][0]
+        assert url == f"{BASE_URL}/api/generate"
+
+    async def test_ignores_exceptions_silently(self):
+        client = AsyncMock()
+        client.__aenter__ = AsyncMock(return_value=client)
+        client.__aexit__ = AsyncMock(return_value=False)
+        client.post = AsyncMock(side_effect=Exception("connection refused"))
+        with patch("vram_manager.httpx.AsyncClient", return_value=client):
+            mgr = _make_manager()
+            # Should not raise
+            await mgr._flush("qwen3:4b")
+
+
+# ── _prewarm ───────────────────────────────────────────────────────────────────
+
+class TestPrewarm:
+    async def test_sends_keep_alive_300(self):
+        client = _mock_client(post_response=MagicMock())
+        with patch("vram_manager.httpx.AsyncClient", return_value=client):
+            mgr = _make_manager()
+            await mgr._prewarm("qwen3:4b")
+        _, kwargs = client.post.await_args
+        body = kwargs.get("json") or client.post.call_args[1].get("json") or client.post.call_args[0][1]
+        assert body["keep_alive"] == 300
+        assert body["model"] == "qwen3:4b"
+
+    async def test_ignores_exceptions_silently(self):
+        client = AsyncMock()
+        client.__aenter__ = AsyncMock(return_value=client)
+        client.__aexit__ = AsyncMock(return_value=False)
+        client.post = AsyncMock(side_effect=Exception("timeout"))
+        with patch("vram_manager.httpx.AsyncClient", return_value=client):
+            mgr = _make_manager()
+            await mgr._prewarm("qwen3:4b")
+
+
+# ── _poll_evicted ──────────────────────────────────────────────────────────────
+
+class TestPollEvicted:
+    async def test_returns_true_when_models_absent(self):
+        resp = MagicMock()
+        resp.json.return_value = {"models": [{"name": "some_other_model"}]}
+        client = _mock_client(get_response=resp)
+        with patch("vram_manager.httpx.AsyncClient", return_value=client):
+            mgr = _make_manager()
+            result = await mgr._poll_evicted(["qwen3:4b", "qwen2.5:1.5b"], timeout=5)
+        assert result is True
+
+    async def test_returns_false_on_timeout_when_model_still_loaded(self):
+        resp = MagicMock()
+        resp.json.return_value = {"models": [{"name": "qwen3:4b"}]}
+        client = _mock_client(get_response=resp)
+        with patch("vram_manager.httpx.AsyncClient", return_value=client):
+            mgr = _make_manager()
+            result = await mgr._poll_evicted(["qwen3:4b"], timeout=0.1)
+        assert result is False
+
+    async def test_returns_true_immediately_if_already_empty(self):
+        resp = MagicMock()
+        resp.json.return_value = {"models": []}
+        client = _mock_client(get_response=resp)
+        with patch("vram_manager.httpx.AsyncClient", return_value=client):
+            mgr = _make_manager()
+            result = await mgr._poll_evicted(["qwen3:4b"], timeout=5)
+        assert result is True
+
+    async def test_handles_poll_error_and_continues(self):
+        """If /api/ps errors, polling continues until timeout."""
+        client = AsyncMock()
+        client.__aenter__ = AsyncMock(return_value=client)
+        client.__aexit__ = AsyncMock(return_value=False)
+        client.get = AsyncMock(side_effect=Exception("network error"))
+        with patch("vram_manager.httpx.AsyncClient", return_value=client):
+            mgr = _make_manager()
+            result = await mgr._poll_evicted(["qwen3:4b"], timeout=0.2)
+        assert result is False
+
+
+# ── enter_complex_mode / exit_complex_mode ─────────────────────────────────────
+
+class TestComplexMode:
+    async def test_enter_complex_mode_returns_true_on_success(self):
+        mgr = _make_manager()
+        mgr._flush = AsyncMock()
+        mgr._poll_evicted = AsyncMock(return_value=True)
+        result = await mgr.enter_complex_mode()
+        assert result is True
+
+    async def test_enter_complex_mode_flushes_medium_models(self):
+        mgr = _make_manager()
+        mgr._flush = AsyncMock()
+        mgr._poll_evicted = AsyncMock(return_value=True)
+        await mgr.enter_complex_mode()
+        flushed = {call.args[0] for call in mgr._flush.call_args_list}
+        assert "qwen3:4b" in flushed
+        assert "qwen2.5:1.5b" in flushed
+
+    async def test_enter_complex_mode_returns_false_on_eviction_timeout(self):
+        mgr = _make_manager()
+        mgr._flush = AsyncMock()
+        mgr._poll_evicted = AsyncMock(return_value=False)
+        result = await mgr.enter_complex_mode()
+        assert result is False
+
+    async def test_exit_complex_mode_flushes_complex_and_prewarms_medium(self):
+        mgr = _make_manager()
+        mgr._flush = AsyncMock()
+        mgr._prewarm = AsyncMock()
+        await mgr.exit_complex_mode()
+        # Must flush 8b
+        flushed = {call.args[0] for call in mgr._flush.call_args_list}
+        assert "qwen3:8b" in flushed
+        # Must prewarm medium models
+        prewarmed = {call.args[0] for call in mgr._prewarm.call_args_list}
+        assert "qwen3:4b" in prewarmed
+        assert "qwen2.5:1.5b" in prewarmed