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>

apps/coder/src/services/provider-registry.ts

@@ -13,8 +13,7 @@ export interface ProviderDef {
  * - boocode: llama-swap only
  * - opencode: ACP probe + mergeLlamaSwap (prefixed llama-swap/* ids)
  * - qwen: ACP probe + merge ~/.qwen/settings.json; PTY fallback reads settings only
- * - cursor: ACP probe + cursor-agent models CLI fallback
- * - goose / copilot: ACP probe only
+ * - goose: ACP probe only
  * - claude: static manifest models + thinking options
  */
 export const PROVIDERS: ProviderDef[] = [