feat: implement drizzle adapter

[scarlettnik]

What

Adds the YDB Drizzle adapter package, comprehensive adapter test coverage, package-surface validation, examples, and related CI/infrastructure updates.

Why

This adds native YDB JS SDK integration with Drizzle ORM, allowing users to define schemas, build queries, run migrations, execute transactions, and use YDB through the Drizzle API with verified adapter behavior.

Testing

Adds comprehensive coverage for the YDB Drizzle adapter:

• unit tests for SQL generation, dialect behavior, schema/table helpers, column types, mutation builders, migrations, transactions, prepared queries, relational queries, and the public API contract
• live integration tests against YDB for adapter methods, CRUD flows, raw SQL, migrations, relations, transactions, select features, type round-trips, and known YQL gaps
• packages/drizzle-adapter/scripts/check-package-surface.mjs to validate the published package surface, allowed runtime exports, forbidden deep imports, and packed package contents
• example-level checks for the Drizzle adapter lab/example

Verification commands:

• npm run test --workspace @ydbjs/drizzle-adapter
• npm run test:unit --workspace @ydbjs/drizzle-adapter
• npm run test:live --workspace @ydbjs/drizzle-adapter
• npm run check:surface --workspace @ydbjs/drizzle-adapter
• npm run build --workspace @ydbjs/drizzle-adapter
• npm run check --workspace @ydbjs/examples-drizzle-adapter-lab

Examples

A graphical app tha tutilizes almost all adapter's methods is implemented in scarlettnik#1

Checklist

• Changeset added (if package changes)
• README updated (if public API changed)