v0.3.1 — local-model fixes

Fixed

• The Ollama preset pointed at a thinking model. Ollama's plain
  qwen3-vl:8b and qwen3-vl:30b tags are thinking builds: they spend the
  whole reply thinking, so the agent got no answer and no tool call, and the
  model test in Settings said tools didn't work. The preset now uses
  qwen3-vl:8b-instruct (about 6 GB), with qwen3-vl:30b-a3b-instruct (about
  20 GB) as the bigger pick. If you added Ollama before this release, run
  ollama pull qwen3-vl:8b-instruct, then change the model to
  qwen3-vl:8b-instruct in Settings.
  (#3)
• The model test and Fetch models now say why a local model failed. A
  reasoning model that uses the whole test on thinking gets "spent the whole
  budget thinking", with the instruct build to use instead where there is one.
  A local server that answers 403 gets the fix: set OLLAMA_ORIGINS for
  Ollama, or switch on Enable CORS in LM Studio. The message points to the
  README, with a link in the model test. Before, both cases ended in "Tools
  didn't work".