coder(providers): remove retired cursor and copilot providers
Drop both retired providers from BooCoder's provider layer: acp-spawn argv cases, provider-manifest mode blocks + manifest keys, provider-commands maps, the provider-snapshot cursor model-CLI branch (+ orphaned exec/promisify imports), the agent-probe copilot ACP-detect branch, and the now-dead cursor-models module + its test. The PROVIDERS registry array already lacked both. Built-ins unchanged: claude, opencode, goose, qwen, native boocode.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
indifferentketchup
a359a4ab8b