fix(webapp): gate the disable auto-assign button on Vercel permission

Every other action in the Vercel settings form disables itself and explains why
when the role cannot manage the integration. This button did not, so it looked
clickable to a viewer even though the action rejects them.

Author: samejr

apps/webapp/app/routes/resources.orgs.$organizationSlug.projects.$projectParam.env.$envParam.vercel.tsx

@@ -1008,7 +1008,12 @@ function ConnectedVercelProjectForm({
               <Button
                 type="button"
                 variant="warning/small"
-                disabled={isDisablingAutoAssign}
+                disabled={isDisablingAutoAssign || !canManageVercel}
+                tooltip={
+                  canManageVercel
+                    ? undefined
+                    : "You don't have permission to manage the Vercel integration"
+                }
                 LeadingIcon={isDisablingAutoAssign ? SpinnerWhite : undefined}
                 onClick={() =>
                   disableAutoAssignFetcher.submit(