SequelizeJS Decorators

Provides TypeScript decorators (Entity, Column, BelongsTo, HasMany, etc.) for defining Sequelize v6 models declaratively. Current version 6.1.7 aligns with Sequelize major version 6. Ships TypeScript declarations. Requires `experimentalDecorators` and `emitDecoratorMetadata` in tsconfig. Release cadence follows Sequelize major versions. Key differentiator: allows schema definition entirely via decorators, reducing boilerplate versus traditional Sequelize model definitions.