38 feat add support for co relrec relspec relsub domains

[rubentalstra]

This pull request refactors the codebase to consistently restrict mapping, preview, validation, and supplemental configuration logic to only operate on "source domains." It introduces explicit checks and conversions to ensure that these operations are not mistakenly applied to generated or non-source domains, improving correctness and maintainability. Additionally, it updates project persistence logic to only serialize source domains, preparing the codebase for future handling of generated domains.

• Closes: [Feat]: Add support for CO, RELREC, RELSPEC, RELSUB domains #38

Domain Handling Consistency

• Updated all mapping, preview, and validation logic in domain_editor.rs to operate only on source domains by adding explicit .as_source() or .as_source_mut() checks, preventing unintended operations on other domain types. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
• Ensured that preview and validation input structures, as well as supplemental configuration, are always sourced from the correct domain type. [1] [2]

Project Persistence Updates

• Modified project save logic in project.rs to only persist file-based data (snapshots and assignments) for source domains, skipping generated domains and setting up for future extensibility.

Validation and Mapping State Management

• Replaced calls to invalidate_validation() with direct manipulation of the validation_cache field for source domains, simplifying the cache invalidation process. [1] [2] [3] [4] [5] [6] [7] [8]

Export Logic Restriction

• Updated export logic to only collect "not collected" variables from source domains, avoiding errors or irrelevant data from other domain types.

Codebase Cleanup

• Updated imports and type usage in project.rs to support the new SourceDomainSnapshot and related structures.