feat(DiagramLayout): Route.general names the general a specialization edge is routed to

[devin-ai-integration]

Summary

A SysML v2 specialization (part def Sub :> Sup;) declares no element of its own, so metadata DiagramLayout::Route about … had nothing to name for the inheritance line a tree diagram draws — a Cameo BDD's generalization routes could not be carried into the migrated model. Route gains

ref general : Base::Anything[0..1];

A Route about the specific element typing general steers the edge drawn to that general, one Route per general; a Route without general keeps steering the annotated element's own edge (a connection def Sub :> Base still routes its own line):

part def Detector;
part def Sensor;
part def 'Secondary Electron Detector' :> Detector;
part def 'Backscattered Electron Detector' :> Detector, Sensor;

view positioned {
    expose Microscope::*;
    metadata Route about 'Secondary Electron Detector' {
        points = (240, 160, 240, 110, 315, 110, 315, 53);
        ref :>> general : Detector;
    }
    metadata Route about 'Backscattered Electron Detector' {
        points = (440, 160, 440, 110, 315, 110, 315, 53);
        ref :>> general : Detector;
    }
    metadata Route about 'Backscattered Electron Detector' {
        points = (520, 160, 520, 120, 535, 120, 535, 53);
        ref :>> general : Sensor;
    }
    render asTreeDiagram;
}

The typed-redefinition form is the one MigrationMetadata::DeferredEvent already uses for signal; a value binding (general = Detector) is not a valid feature value for the pilot, and a standalone KerML specialization member is not admitted in SysML v2 textual notation, so neither was an option.

engine-contract.json lists general on DiagramLayout::Route and the new element DiagramLayout::Route::general, both read by internal/semantic/semantics/layout.go in the OpenSysML pull request that re-pins this change (Open-MBEE/OpenSysML#1166). Additive: semver MINOR, contract unchanged.

Verified: ./scripts/validate-libraries.sh — 0 errors, 0 warnings on the pinned pilot (2026-08, 0.62.0); ./scripts/check-engine-contract.sh --base origin/main clean; ./scripts/check-readme-table.sh clean; the example above validates with 0 errors under the pilot with this library and under OpenSysML.

Link to Devin session: https://nasa-jpl-demo.devinenterprise.com/sessions/850d56a6ed3e4b39b7a1dc2b4b9ec6d8
Open in Devin Desktop: https://nasa-jpl-demo.devinenterprise.com/desktop/session/850d56a6ed3e4b39b7a1dc2b4b9ec6d8?variant=devin
Requested by: @HuiJun

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.

[devin-ai-integration]

The required check (Validate the extension libraries) is green. The advisory "OpenSysML against these libraries" job is red on two tests that do not touch this change: TestKerMLFeatureMetaclassClassification reads examples/pilot-corpora, which that job does not download, and TestExecutionConformance/verification_chain_package_usage_value* fails identically on OpenSysML develop (fix in Open-MBEE/OpenSysML#1160). Every library- and contract-related package passed, tests/hygiene included. Open-MBEE/OpenSysML#1166 re-pins this commit once it is on main.