fix(lakebase): getLakebaseOrmConfig() pool settings don't reach TypeORM or Sequelize #730

Follow-up to #719, from review.

Problem

getLakebaseOrmConfig() returns pool settings (maxLifetimeSeconds, max, idleTimeoutMillis, connectionTimeoutMillis, statement_timeout, …) at the top level of the config object. Neither ORM it's documented for reads them from there, so TypeORM and Sequelize users don't get connection recycling (#719) or any of the other pool settings.

Recycling matters because Lakebase checks the OAuth token only when a connection opens. Access granted through Unity Catalog claims in the token stops working on a connection that stays open for hours: queries fail with 42501 permission denied while the connection stays up.

TypeORM (0.3.28)

PostgresDriver.createPool() builds the pg.Pool options from a fixed set of fields (host, user, password, database, port, ssl, connectTimeoutMS, applicationName, poolSize) and then options.extra. It never reads top-level pg-pool options, so maxLifetimeSeconds, max, idleTimeoutMillis and the timeouts are all dropped. This was already true before #719.

Sequelize (6.37.7)

Sequelize doesn't use pg-pool. It creates pg.Client instances itself and pools them with sequelize-pool, which recycles by use count (pool.maxUses) but has no age-based option. maxLifetimeSeconds has no counterpart.

Proposed fix

• TypeORM: have getLakebaseOrmConfig() also return the pool settings under extra. Check with a test that Sequelize ignores the extra key, so one return shape still works for both.
• Sequelize: recycle by age with pool.validate, which sequelize-pool calls on each checkout and which destroys the connection when it returns false. Record when each connection is first seen in a WeakMap and reject it once it's older than the lifetime. A custom validate replaces Sequelize's built-in check (dialects/postgres/connection-manager.js), so it must repeat that check too. Alternatively, document that Sequelize users need to handle this themselves.
• Update apps/dev-playground/server/lakebase-examples/typeorm-example.ts and sequelize-example.ts, and add tests that a TypeORM DataSource and a Sequelize instance actually get the lifetime.