fix(ui): R3 S1 review fixes — don't blank data on transient refetch errors

- The honest-state branch now guards on `isError && !data`, so a background/window-focus refetch
  failure keeps already-visible content instead of replacing the list with a full error screen
  (regression the bare `isError` introduced). Applied to AuditLog, Channels, ChannelDiscovery,
  PlexBrowse, PlexPlaylistView, Messages(people), Feed — matching the guard already used in
  Messages(conversations)/NotificationsPanel/Scheduler.
- Drop the unused DataTable loading/error/onRetry props (every table page uses the outer
  StateMessage branch, not the props) — reverts DataTable to its simple empty block.
- StateMessage announces errors with role=alert/aria-live=assertive (was polite for all tones).
- Remove the now-unused common.empty string (en+hu), left over from the removed QueryState render-prop.

frontend/src/components/AuditLog.tsx

@@ -54,7 +54,7 @@ export default function AuditLog() {
     <div className="p-4 max-w-5xl w-full mx-auto">
       <Section card title={t("audit.title")}>
         <p className="text-xs text-muted leading-relaxed mb-3">{t("audit.intro")}</p>
-        {q.isError ? (
+        {q.isError && !q.data ? (
           <StateMessage tone="error" onRetry={() => q.refetch()}>
             {t("common.loadError")}
           </StateMessage>

frontend/src/components/ChannelDiscovery.tsx

@@ -224,7 +224,7 @@ export default function ChannelDiscovery({
         </div>
       </PageToolbar>
       <div className="px-4 pb-4 max-w-[96rem] mx-auto">
-        {query.isError ? (
+        {query.isError && !query.data ? (
           <StateMessage tone="error" onRetry={() => query.refetch()}>
             {t("common.loadError")}
           </StateMessage>

frontend/src/components/Channels.tsx

@@ -710,7 +710,7 @@ export default function Channels() {
             (status chips + pager) rides in the fixed band right above it (controlsInBand). The
             card layout swaps the table for a virtualized grid over the same rows (its pager and
             status chips ride in the fixed band above instead). */}
-          {channelsQuery.isError ? (
+          {channelsQuery.isError && !channelsQuery.data ? (
             <StateMessage tone="error" onRetry={() => channelsQuery.refetch()}>
               {t("common.loadError")}
             </StateMessage>

frontend/src/components/DataTable.tsx

@@ -4,7 +4,6 @@ import { sortRows, cycleSort, type SortState } from "../lib/columnSort";
 import Pager, { hasPagerContent } from "./Pager";
 import { PageToolbar } from "./PageShell";
 import { ColumnHead, alignClass, filterRows, type Column, type FilterMap } from "./tableHeader";
-import { StateMessage } from "./QueryState";
 
 // A reusable, client-side data table: per-column sort + filter (in the header) + pagination,
 // with its sort/filter/page state optionally persisted to localStorage so a reload (F5) keeps
@@ -45,9 +44,6 @@ export default function DataTable<T>({
   pageSizeOptions = [10, 25, 50, 100],
   persistKey,
   emptyText,
-  loading = false,
-  error = false,
-  onRetry,
   rowClassName,
   controlsPosition = "bottom",
   controlsLeading,
@@ -65,12 +61,6 @@ export default function DataTable<T>({
   pageSizeOptions?: number[];
   persistKey?: string;
   emptyText?: string;
-  // Honest states (R3): when the caller's query is loading or errored, pass these so the table
-  // shows a loading / error(+retry) message instead of an "empty" list that lies about a failed
-  // fetch. `error` suppresses the empty-text; `onRetry` wires the retry button.
-  loading?: boolean;
-  error?: boolean;
-  onRetry?: () => void;
   rowClassName?: (row: T) => string;
   controlsPosition?: "top" | "bottom" | "both";
   controlsLeading?: ReactNode;
@@ -256,17 +246,11 @@ export default function DataTable<T>({
         ))}
       </div>
 
-      {error ? (
-        <StateMessage tone="error" onRetry={onRetry}>
-          {t("common.loadError")}
-        </StateMessage>
-      ) : loading && paged.length === 0 ? (
-        <StateMessage>{t("common.loading")}</StateMessage>
-      ) : paged.length === 0 ? (
+      {paged.length === 0 && (
         <div className="text-muted py-8 text-center text-sm">
           {emptyText ?? t("datatable.empty")}
         </div>
-      ) : null}
+      )}
 
       {controlsPosition === "bottom" && controls}
       {controlsPosition === "both" && bottomControls}

frontend/src/components/Feed.tsx

@@ -494,7 +494,7 @@ export default function Feed({
   }
 
   if (query.isLoading) return <div className="p-8 text-muted">{t("feed.loading")}</div>;
-  if (query.isError)
+  if (query.isError && !query.data)
     return (
       <StateMessage tone="error" onRetry={() => query.refetch()}>
         {t("feed.loadError")}

frontend/src/components/Messages.tsx

@@ -225,7 +225,7 @@ function Directory({ onPick, onBack }: { onPick: (u: MessageUser) => void; onBac
         placeholder={t("messages.searchPeople")}
         className="w-full bg-card border border-border rounded-xl px-3 py-2 text-sm outline-none focus:border-accent"
       />
-      {q.isError ? (
+      {q.isError && !q.data ? (
         <StateMessage tone="error" onRetry={() => q.refetch()}>
           {t("common.loadError")}
         </StateMessage>

frontend/src/components/PlexBrowse.tsx

@@ -358,7 +358,7 @@ export default function PlexBrowse() {
         </div>
       )}
 
-      {browseQ.isError ? (
+      {browseQ.isError && !browseQ.data ? (
         <StateMessage tone="error" onRetry={() => browseQ.refetch()}>
           {t("common.loadError")}
         </StateMessage>

frontend/src/components/PlexPlaylistView.tsx

@@ -577,7 +577,7 @@ export default function PlexPlaylistView({
           </button>
         </div>
 
-        {q.isError ? (
+        {q.isError && !q.data ? (
           <StateMessage tone="error" onRetry={() => q.refetch()}>
             {t("common.loadError")}
           </StateMessage>

frontend/src/components/QueryState.tsx

@@ -22,8 +22,9 @@ export function StateMessage({
   return (
     <div
       className={`flex flex-col items-center gap-3 py-10 text-sm text-muted ${className}`}
-      role="status"
-      aria-live="polite"
+      // An error is announced promptly (assertive); a plain loading line is polite.
+      role={tone === "error" ? "alert" : "status"}
+      aria-live={tone === "error" ? "assertive" : "polite"}
     >
       <span className="inline-flex items-center gap-2 text-center">
         {tone === "error" && <AlertTriangle className="w-4 h-4 shrink-0 text-red-400" />}
@@ -42,7 +43,8 @@ export function StateMessage({
   );
 }
 
-// The honest-state convention every page now follows: check `isError` BEFORE the empty branch so a
-// failed fetch renders this message (with Retry) instead of the page's "empty" text — the R3 bug
-// where a backend restart read as "No channels". `StateMessage` is the shared building block;
-// pages wire it into their existing loading/empty ternary (and DataTable takes loading/error props).
+// The honest-state convention every page now follows: check `isError && <no data>` BEFORE the empty
+// branch, so a failed fetch renders this message (with Retry) instead of the page's "empty" text
+// — the R3 bug where a backend restart read as "No channels". The `&& <no data>` guard matters: a
+// transient refetch error while data is already on screen keeps the data rather than blanking it to
+// an error. `StateMessage` is the shared building block pages wire into their loading/empty ternary.

frontend/src/i18n/locales/en/common.json

@@ -19,6 +19,5 @@
   "demoSharedNotice": "You're in the shared demo account. Everything you do here — playlists, hidden videos, settings — is communal and may be changed by other demo visitors at the same time.",
   "backToTop": "Back to top",
   "retry": "Retry",
-  "loadError": "Couldn't load this — check your connection and try again.",
-  "empty": "Nothing here yet."
+  "loadError": "Couldn't load this — check your connection and try again."
 }

frontend/src/i18n/locales/hu/common.json

@@ -19,6 +19,5 @@
   "demoSharedNotice": "Egy közös demo fiókban vagy. Minden, amit itt csinálsz — lejátszási listák, elrejtett videók, beállítások — közös, és más demo látogatók egyszerre módosíthatják.",
   "backToTop": "Vissza a tetejére",
   "retry": "Újra",
-  "loadError": "Nem sikerült betölteni — ellenőrizd a kapcsolatot, és próbáld újra.",
-  "empty": "Itt még nincs semmi."
+  "loadError": "Nem sikerült betölteni — ellenőrizd a kapcsolatot, és próbáld újra."
 }