fix(setup): recover legacy #1140 split enable state

entire enable early-returned on the merged IsEnabled view, so it could not recover the split state a pre-fix binary left on disk: committed settings.json enabled:false masked by settings.local.json enabled:true (local wins in the merge). The merged view read enabled, the early return fired, and the committed project file the user cares about stayed disabled forever — even with an explicit --project. This is issue #1140 step 4.

Resolve the target scope first and only short-circuit when the merged view is enabled AND the resolved target file is not itself explicitly disabled (new scopeExplicitlyDisabled helper reads the file's own raw enabled key). Otherwise fall through and flip the target scope.