feat(ui): shared LoadingState — a centered accent spinner instead of plain loading text

Replaces the plain "Loading…" text in every R3 loading branch with a single shared LoadingState
(a spinning lucide Loader2 in the accent colour + label, centered, role=status/aria-live) — one
component so all loads read the same and can be swapped for skeletons later in one place. Applied
across Feed, Channels, ChannelDiscovery, AuditLog, NotificationsPanel, Messages, Scheduler, Stats,
PlexBrowse (grid + subviews), PlexPlaylistView, ConfigPanel, DownloadCenter, AdminUsers, ChatThread.
Left the small "load more" footer and lazy Suspense fallbacks as-is.

frontend/src/components/AuditLog.tsx

@@ -8,7 +8,7 @@ import { LS } from "../lib/storage";
 import { Section } from "./ui/form";
 import { useConfirm } from "./ConfirmProvider";
 import DataTable from "./DataTable";
-import { StateMessage } from "./QueryState";
+import { LoadingState, StateMessage } from "./QueryState";
 import { auditColumns } from "./auditColumns";
 
 // Admin-only audit trail: an append-only who/what/when log of admin actions + scheduler run
@@ -59,7 +59,7 @@ export default function AuditLog() {
             {t("common.loadError")}
           </StateMessage>
         ) : q.isLoading ? (
-          <div className="text-muted py-8">{t("common.loading")}</div>
+          <LoadingState />
         ) : rows.length === 0 ? (
           <p className="text-sm text-muted">{t("audit.empty")}</p>
         ) : (