Ollama not running - silent failure with misleading UI

[daveshenal]

Describe the bug

• When Ollama is not running, the Models page shows an empty model list with a "download models" prompt, implying no models are installed. When the user tries to pull a model it silently fails with no error message.

Expected behavior

• On startup, detect if Ollama is reachable at localhost:11434
• If not reachable, show a clear message: "Ollama is not running. Please start Ollama and restart Outpost." or similar
• Disable model download and chat until Ollama is detected
• Optionally: poll every few seconds and auto-recover when Ollama comes online

Steps to reproduce

• Make sure Ollama is not running
• Open Outpost
• Go to Models page - shows empty list with install prompt
• Try to pull a model - silently fails

Affected files

• frontend/src/pages/ModelsPage.jsx - needs Ollama status check
• frontend/src/store.js - fetchModels swallows errors silently
• backend/server.py - /models endpoint returns empty list on Ollama failure with no status indicator