Add Ollama Provider

Routes an agent group to a local Ollama instance instead of the Anthropic API. See docs/ollama.md for how this works and the tradeoffs involved.

Prerequisites

1. Ollama is installed and running on the host — verify: curl -s http://localhost:11434/api/tags
2. A model is pulled — e.g. ollama pull gemma4 or ollama pull qwen3-coder
3. The agent group already exists — run /init-first-agent first if needed

1. Check source support

The feature requires two fields in ContainerConfig (env and blockedHosts) and their corresponding wiring in container-runner.ts. Check if already present:

grep -c 'blockedHosts' src/container-config.ts src/container-runner.ts