B5: default model auto-pull on first start (v0.19.1)

model_pull.py: ensure_model() checks llama-server availability at
startup, falls back to Ollama pull API if model not found.
Integrated into app.py lifespan after assess_hardware().
11 tests cover all paths: available/unreachable/pull success/fail.

tests/test_model_pull.py

@@ -0,0 +1,142 @@
+import asyncio
+
+import httpx
+
+from model_pull import ensure_model, _model_available_on_llama, _model_available_on_ollama, _pull_via_ollama
+
+
+class _MockAsyncResponse:
+    def __init__(self, status_code=200, json_data=None):
+        self.status_code = status_code
+        self._json_data = json_data or {}
+
+    def json(self):
+        return self._json_data
+
+
+class _MockStreamResponse:
+    def __init__(self, status_code=200, lines=None):
+        self.status_code = status_code
+        self._lines = lines or []
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, *args):
+        pass
+
+    def aiter_lines(self):
+        class _AIter:
+            def __init__(self, lines):
+                self._lines = iter(lines)
+            def __aiter__(self):
+                return self
+            async def __anext__(self):
+                try:
+                    return next(self._lines)
+                except StopIteration:
+                    raise StopAsyncIteration
+        return _AIter(self._lines)
+
+
+def _mock_models_on_llama(*models):
+    async def _get(*args, **kwargs):
+        return _MockAsyncResponse(json_data={
+            "data": [{"id": m} for m in models]
+        })
+    return _get
+
+
+async def _mock_ollama_available(*args, **kwargs):
+    return _MockAsyncResponse(status_code=200, json_data={"name": "qwen2.5:latest"})
+
+
+async def _mock_ollama_unavailable(*args, **kwargs):
+    raise httpx.ConnectError("refused")
+
+
+def _mock_ollama_pull_ok(*args, **kwargs):
+    return _MockStreamResponse(200, [
+        '{"status": "pulling manifest"}',
+        '{"status": "success"}',
+    ])
+
+
+def _mock_ollama_pull_fail(*args, **kwargs):
+    return _MockStreamResponse(500, [])
+
+
+def _mock_ollama_connect_error(*args, **kwargs):
+    raise httpx.ConnectError("refused")
+
+
+def test_available_on_llama(monkeypatch):
+    monkeypatch.setattr(httpx.AsyncClient, "get", _mock_models_on_llama("qwen2.5-7b-instruct"))
+    assert asyncio.run(_model_available_on_llama("qwen2.5-7b-instruct")) is True
+    assert asyncio.run(_model_available_on_llama("nonexistent-model")) is False
+
+
+def test_available_on_llama_unreachable(monkeypatch):
+    async def _connect_error(*args, **kwargs):
+        raise httpx.ConnectError("refused")
+    monkeypatch.setattr(httpx.AsyncClient, "get", _connect_error)
+    assert asyncio.run(_model_available_on_llama("qwen2.5-7b-instruct")) is False
+
+
+def test_available_on_ollama(monkeypatch):
+    monkeypatch.setattr(httpx.AsyncClient, "post", _mock_ollama_available)
+    assert asyncio.run(_model_available_on_ollama("qwen2.5:latest")) is True
+
+
+def test_available_on_ollama_unreachable(monkeypatch):
+    monkeypatch.setattr(httpx.AsyncClient, "post", _mock_ollama_unavailable)
+    assert asyncio.run(_model_available_on_ollama("qwen2.5:latest")) is False
+
+
+def test_pull_via_ollama_success(monkeypatch):
+    monkeypatch.setattr(httpx.AsyncClient, "stream", _mock_ollama_pull_ok)
+    assert asyncio.run(_pull_via_ollama("qwen2.5:latest")) is True
+
+
+def test_pull_via_ollama_fail(monkeypatch):
+    monkeypatch.setattr(httpx.AsyncClient, "stream", _mock_ollama_pull_fail)
+    assert asyncio.run(_pull_via_ollama("qwen2.5:latest")) is False
+
+
+def test_pull_via_ollama_connect_error(monkeypatch):
+    monkeypatch.setattr(httpx.AsyncClient, "stream", _mock_ollama_connect_error)
+    assert asyncio.run(_pull_via_ollama("qwen2.5:latest")) is False
+
+
+def test_ensure_model_already_on_llama(monkeypatch):
+    monkeypatch.setattr(httpx.AsyncClient, "get", _mock_models_on_llama("qwen2.5-7b-instruct"))
+    assert asyncio.run(ensure_model("qwen2.5-7b-instruct")) is True
+
+
+def test_ensure_model_not_on_llama_but_on_ollama(monkeypatch):
+    async def _get(*args, **kwargs):
+        return _MockAsyncResponse(json_data={"data": []})
+
+    monkeypatch.setattr(httpx.AsyncClient, "get", _get)
+    monkeypatch.setattr(httpx.AsyncClient, "post", _mock_ollama_available)
+    assert asyncio.run(ensure_model("qwen2.5-7b-instruct")) is True
+
+
+def test_ensure_model_needs_pull(monkeypatch):
+    async def _get(*args, **kwargs):
+        return _MockAsyncResponse(json_data={"data": []})
+
+    monkeypatch.setattr(httpx.AsyncClient, "get", _get)
+    monkeypatch.setattr(httpx.AsyncClient, "post", _mock_ollama_unavailable)
+    monkeypatch.setattr(httpx.AsyncClient, "stream", _mock_ollama_pull_ok)
+    assert asyncio.run(ensure_model("qwen2.5-7b-instruct")) is True
+
+
+def test_ensure_model_pull_fails(monkeypatch):
+    async def _get(*args, **kwargs):
+        return _MockAsyncResponse(json_data={"data": []})
+
+    monkeypatch.setattr(httpx.AsyncClient, "get", _get)
+    monkeypatch.setattr(httpx.AsyncClient, "post", _mock_ollama_unavailable)
+    monkeypatch.setattr(httpx.AsyncClient, "stream", _mock_ollama_pull_fail)
+    assert asyncio.run(ensure_model("qwen2.5-7b-instruct")) is False