toolkit pre-rename subtree merge

Chose importing getsentry/cli into an integration branch of getsentry/sentry-mcp, validating the complete monorepo there, then renaming it to getsentry/toolkit over renaming first because pre-rename validation preserves known MCP deployment wiring and makes rollback safer. Keep CLI at packages/cli and docs at apps/cli-docs; use a pnpm workspace without Turbo, independent cli@/mcp@ releases, root-managed patches/catalogs, and later incremental extraction into @sentry/toolkit-core.