- Add `issue attach` command to attach files to issues
- Add `--attach` flag on `issue comment add`
- Show attachments section in `issue view` with auto-download
- Add `attachment_dir` and `auto_download_attachments` config options
- Add network permission for storage.googleapis.com (upload destination)
Add built-in credential storage for managing multiple Linear workspaces:
- ~/.config/linear/credentials.toml stores API keys by workspace slug
- auth login: add credentials (auto-detects workspace from API)
- auth logout: remove credentials
- auth list: show configured workspaces with org/user info
- auth default: set the default workspace
- global -w/--workspace flag to target specific workspace
API key precedence: CLI flag > env var > config > workspace flag > project workspace > default