bug: `generate_from_raw` hanging when ollama under load

[psschwei]

In the process of testing #567 I encountered an issue where test/core/test_component_typing.py::test_generating was timing out after 15 minutes and failing. Seems like I had overloaded ollama by running for i in {1..10}; do uv run pytest test/core -v; done and the test failed on the fourth or fifth run.

Doing a little bit of digging, it seems like the issue happened here:

mellea/mellea/backends/ollama.py

Line 466 in c4cb59f

responses = await asyncio.gather(*coroutines, return_exceptions=True)

Because there's no timeout, if Ollama stalls on any of the concurrent requests (like it seems happened when I ran this test over and over and over again) the entire call hangs indefinitely.

There's a couple of different ways we could fix this, but probably the easiest would be to set a timeout on the underlying ollama.AsyncClient:

mellea/mellea/backends/ollama.py

Line 201 in c4cb59f

_async_client = ollama.AsyncClient(self._base_url)

Ideally we'd make the timeout configurable too (so users could set it when creating the backend?)

[psschwei]

Looks like @planetf1 may have already reported this in #599 (though they might be slightly different?)

[LuminoNectar]

I would like to tackle this bug! Can this be assigned to me?