Move the 17 global lookup arrays from resources/data/admin_constants.php
into PSR-4 classes and enums, eliminating the last big pile of `global`
reference data.
New XcVm\Core\Reference\* (const + static accessors, FfmpegBinaries-style):
GeoReference, LocaleReference, DeviceReference, UiReference,
PermissionReference, StatusBadge. New XcVm\Core\Enum\* (backed enums with
label()/options(), ModuleState-style): Theme (int), ResellerAction and
ClientFilter (string).
All consumers migrated off `global $rX` / `$GLOBALS['rX']` and the
BaseAdminController extract bridge: TableController, DashboardController,
SearchAjaxController, SettingsController, ResellerAPI and
ResellerLoginController call the classes directly, and 21 view templates
import them via `use`. The extract whitelist entries, the bootstrap
require and admin_constants.php itself are removed.
Fixes a latent bug: TableController read $rClientFilters without a
`global`, so the client-request log showed raw status codes instead of
labels; ClientFilter::labelFor() now resolves them.
The reference classes and the three new enums are excluded from the
load-balancer build (all consumers are already MAIN-only).
Adds unit tests for the enums, StatusBadge and the reference data.
