refactor: migrate codebase from CommonJS to ES modules}
- Rename all .js source files to .mjs for native ES module support - Rename Gruntfile.js to Gruntfile.cjs for CommonJS compatibility - Convert require()/module.exports to import/export syntax throughout - Replace Koa HTTP framework with native Node.js HTTP server - Add HTTP basic authentication support (src/lib/http-auth.mjs) - Add license tier system (src/lib/license-tier.mjs) - Add build compression script (scripts/build-compressed.mjs) - Add bcrypt password utility (bin/bcrypt-password.mjs) - Add new socket.io request handlers: client-kill, client-list, connections-reorder, key-export, key-import, key-json-set, license-status, memory-top-keys, monitor-info, search-index-create, search-index-drop, search-index-info, search-list, search-query - Expand check-license and cli modules with additional functionality - Update connection-connect with revised cluster and auth handling - Update key-get, key-new-or-set, key-set, and set-subscription logic - Enhance shared.mjs and socket.mjs with expanded socket event routing - Update package.json dependencies and scripts for ESM configuration - Update LICENSE and README.md - Remove AGENTS.md - Update .gitignore and .npmignore for new file structure - Update yarn.lock with revised dependency tree