add ollama context size

[itsmebcc]

ollama functions very poorly in all scenarios as the amount of context given by default is 2048 which means it handles the system prompt and that is about it. If you modify src/lib/providers/ollama.ts and on line 29 add:

      numCtx: 8192

then the ollama model will actually have enough context to see the system prompt, as well as the context added by the search results.