Generate dedicated native Specifications 5 runners without changing application startup #767

Generated Cratis applications still receive Specifications 4/xUnit 2 test dependencies, blocking migration of generated samples to native Specifications 5/xUnit v3 execution. Update the owning scaffold to emit a dedicated net10.0 executable specification runner while preserving application startup and production target frameworks. Keep test dependency pins and their supported catalog aligned, and prove regeneration through the supported CLI route with generated build and nonzero specification discovery. Add regressions for project separation, dependency versions, naming/root-namespace behavior and CI execution. This is the focused shipping scaffold dependency of #762 and Cratis/Samples#667; it does not authorize broad dependency updates or hand-edited generated sample output.

Status

State: Parked — blocked on the scaffold decision (the spec5-xunit3 branch belongs to Stage#762).
Branch: spec5-xunit3 @ 94892b2
Delivered: Nothing for the scaffold; the Specifications 5 / xUnit v3 branch lands under #762.
Remaining: Generated-app scaffold.
Next step: When the scaffold approach is decided: write a plan for it and implement.