Support file-per-root model folders and incomplete root validation

[sergej-koscejev]

Parent

Parent: #1

What to build

Teach mops validate to treat a file-per-root model folder as one complete validation target and a single .mpsr root file as incomplete validation. A file-per-root model folder consists of .model metadata plus direct .mpsr root files and supports model-wide structural checks across those roots.

Acceptance criteria

• mops validate <model-folder> recognizes a file-per-root model folder from .model metadata and direct .mpsr files.
• Direct .mpsr files in the folder are validated as one model-wide target.
• Nested .mpsr files are not included in the model target.
• Duplicate node IDs are detected across all direct root files in the model folder.
• mops validate <root.mpsr> runs incomplete validation instead of failing solely because sibling roots are missing.
• Incomplete validation is represented as a non-error finding or report status that does not by itself cause exit code 1.
• Tests cover complete file-per-root folders, model-wide duplicate node IDs, ignored nested roots, and incomplete single-root validation.

Blocked by

• Blocked by: Validate node ID syntax and duplicate IDs in standalone models #3