Add EVENTS_RULE_BLOCK constant, events entry in CORE_PACKAGE_GENERATORS
dispatch table, events choice in prompts, and printEventsNextSteps helper.
Events entry emits 15 template files + transpilePackages splice + ESLint
no-restricted-syntax splice (E1 + J blocks). Add byte-identical e2e test
that strips @repo/core-events deps before pnpm install, scaffolds via
gen core-package events, and diffs against the snapshot.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>