Clean up compiler warnings and document Ollama/LiteLLM backends

Remove unused `any_docker_mcp()` function, add `#[allow(unused_imports)]`
and `#[allow(dead_code)]` annotations to suppress false-positive warnings.
Update README.md and HOW-TO-USE.md with Ollama and LiteLLM auth backend
documentation including best-effort compatibility notices.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -49,6 +49,10 @@ Each project can independently use one of:
 
 - **Anthropic** (OAuth): User runs `claude login` inside the terminal on first use. Token persisted in the config volume across restarts and resets.
 - **AWS Bedrock**: Per-project AWS credentials (static keys, profile, or bearer token). SSO sessions are validated before launching Claude for Profile auth.
+- **Ollama**: Connect to a local or remote Ollama server via `ANTHROPIC_BASE_URL` (e.g., `http://host.docker.internal:11434`). Optional model override.
+- **LiteLLM**: Connect through a LiteLLM proxy gateway via `ANTHROPIC_BASE_URL` + `ANTHROPIC_AUTH_TOKEN` to access 100+ model providers. API key stored securely in OS keychain.
+
+> **Note:** Ollama and LiteLLM support is best-effort. Claude Code is designed for Anthropic models, so some features (tool use, extended thinking, prompt caching, etc.) may not work as expected with non-Anthropic models behind these backends.
 
 ### Container Spawning (Sibling Containers)