Added `[Table]` attributes to `Connection`, `Endpoint`, `EndpointAuth`, and `Profile` classes to define database table mappings. Updated `Profile` with schema information.
Introduced a `Profile` navigation property in `RecAction` with a `[ForeignKey]` attribute to establish a relationship with the `Profile` entity. Temporarily marked it as `[NotMapped]` due to a foreign key type mismatch, with a `TODO` to resolve this in the future.
Included `System.ComponentModel.DataAnnotations.Schema` in `using` directives to support these changes.
Introduce a new `Connection` class in the `ReC.Domain.Entities` namespace.
The class is mapped to the `TBDD_CONNECTION` database table and includes
properties for various columns such as `Id`, `Bezeichnung`, `SqlProvider`,
and others. Attributes like `[Key]`, `[Column]`, and `[DatabaseGenerated]`
are used for database mapping. Nullable types are used for all properties.
Added necessary `using` directives for annotations and schema mapping.
