Two test-isolation fixes: (1) an autouse conftest fixture sets OPENJARVIS_NO_UPDATE_CHECK=1 so the CLI's PyPI update-check banner (stderr, merged into CliRunner output) can never pollute JSON/CSV-parsing CLI tests on local runs; CI was already covered by CI=true. (2) test_dense.py's Ollama skip-guard now queries /api/tags and requires nomic-embed-text to be pulled instead of a bare TCP connect, so machines running Ollama without the embed model skip instead of erroring. The probe normalizes all documented OLLAMA_HOST forms (full URL, host:port, bare host) and the Ollama-backed tests construct DenseMemory against that same endpoint rather than the embedder's hard-coded localhost default, with unit tests covering the probe. Related: #645.
