[TASK] Move computer_use to a separate config

[edenreich]

Summary

The computer_use: block adds ~40 lines to config.yaml for a feature that is off by default for most users (screenshot, floating window, rate limiting, per-tool toggles). It has its own subcommand (infer computer-use ...) and is self-contained, so it should live in <configDir>/computer_use.yaml.

Acceptance Criteria

• There is a new config file under <configDir>/computer_use.yaml
• The computer_use section is removed from the main config
• The code considers only the separate config (loading + userspace fallback, mirroring the mcp.yaml / keybindings.yaml pattern)
• infer init seeds computer_use.yaml from in-code defaults
• computer_use.yaml is added to tools.sandbox.protected_paths defaults
• Documentation is adjusted (if applicable)
• It's tested

[ig-semantic-release-bot]

🎉 This issue has been resolved in version 0.104.1 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀