Introduce DB support and repos: add modules/database.js (connection pool + runDDL) and SQL DDL files (data/ddl/*) for servers, users, providers, identities and credentials. Add repository layers: users, servers, providers, identities, credentials. Update server.js to run DDL at startup. Update .env.example with DB settings and bump dependencies in package.json/package-lock.json (add mariadb, bump dotenv/helmet/path-to-regexp/zod and dev tool upgrades). Error handling and logging included for DDL and repo operations.
