closeViewRoleDialog already clears rolePermissionsForView and
roleUsersForView; closeRoleDialog (used by both Edit and Create flows)
did not. With editRole now populating those arrays, leftover state
would otherwise survive a close → open-Create round trip. The Create
template branch doesn't read the arrays today (v-if guarded on
editingRole), so this is defensive — keeps the two close handlers
symmetrical and avoids future regressions if the Create branch ever
starts referencing them.
The dialog reads from rolePermissionsForView / roleUsersForView, but
editRole(role) only ever populated the form fields and showed the
dialog — those arrays were left at whatever state the rest of the page
had set them to. Result: opening Edit Role for a role with existing
permissions showed "No permissions assigned to this role yet", and the
list only "appeared" because adding a permission triggered a refresh.
Mirror viewRole's pattern: clear both arrays, GET /admin/roles/{id},
populate from the response, then show the dialog after $nextTick.
Closes#14
