fix(kb-ui): P0 correctness — TextReader race/errors, outline nav, claims drop, object load-more

- TextReader: monotonic request guard (stale slice can't clobber current) +
  catch with a retry surface instead of a blank panel / unhandled rejection;
  Read-more guarded and shows loading.
- OutlineNav: an explicit section selection now wins over the initial citation
  highlight, so clicking sections works on ?start=&end= views (was inert).
- ObjectViewer: reset section + image on object switch (no bleed across
  citation navigation); catch the blob resolve.
- ObjectList: optional onLoadMore/hasMore/loadingMore (paginated corpuses).
- ClaimsReviewQueue: catch-all "Awaiting review" bucket so a claim the queue
  returned is never silently dropped (e.g. an open-conflict singleton whose
  counterpart is not in the payload).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/components-claims.tsx

@@ -200,9 +200,12 @@ export const ClaimsReviewQueue: FC<ClaimsReviewQueueProps> = ({
   const inConflict = new Set(conflictGroups.flat().map((c) => c.claim_id));
 
   const proposed = claims.filter((c) => c.status === "proposed" && !inConflict.has(c.claim_id));
-  const unreviewed = claims.filter(
+  // Everything the queue returned that isn't a "proposed" card or a rendered
-    (c) => c.status === "active" && c.review_state === "unreviewed" && !inConflict.has(c.claim_id),
+  // conflict pair belongs in "Awaiting review". Filtering narrowly (active +
-  );
+  // unreviewed only) silently dropped anything else the endpoint surfaced —
+  // e.g. a claim flagged open-conflict whose counterpart isn't in this payload
+  // (a singleton group, not rendered as a pair) rendered nowhere at all.
+  const rest = claims.filter((c) => c.status !== "proposed" && !inConflict.has(c.claim_id));
 
   if (claims.length === 0) {
     return <>{emptyState ?? <Empty />}</>;
@@ -230,8 +233,8 @@ export const ClaimsReviewQueue: FC<ClaimsReviewQueueProps> = ({
         ))}
       </Section>
 
-      <Section title="Awaiting review" count={unreviewed.length} hint="Visible already, labelled by tier — review at your pace.">
+      <Section title="Awaiting review" count={rest.length} hint="Visible already, labelled by tier — review at your pace.">
-        {unreviewed.map((c) => (
+        {rest.map((c) => (
           <ClaimCard key={c.claim_id} claim={c} busy={busyId === c.claim_id} onConfirm={onConfirm} onReject={onReject} onReopen={onReopen} onOpenSource={onOpenSource} />
         ))}
       </Section>

src/components-object.tsx

@@ -32,14 +32,19 @@ import {
 export interface ObjectListProps {
   objects: ObjectSummary[];
   onOpen?: (object: ObjectSummary) => void;
+  /** When set, renders a "Load more" affordance (the list is paginated). */
+  onLoadMore?: () => void;
+  hasMore?: boolean;
+  loadingMore?: boolean;
   emptyState?: ReactNode;
   className?: string;
 }
 
-export const ObjectList: FC<ObjectListProps> = ({ objects, onOpen, emptyState, className }) => {
+export const ObjectList: FC<ObjectListProps> = ({ objects, onOpen, onLoadMore, hasMore, loadingMore, emptyState, className }) => {
   if (objects.length === 0 && emptyState) return <>{emptyState}</>;
   return (
-    <ul className={cn("flex flex-col divide-y divide-border rounded-xl border border-border bg-card", className)}>
+    <div className={cn("flex flex-col gap-3", className)}>
+      <ul className="flex flex-col divide-y divide-border rounded-xl border border-border bg-card">
         {objects.map((o) => (
           <li key={o.object_id}>
             <button
@@ -60,6 +65,19 @@ export const ObjectList: FC<ObjectListProps> = ({ objects, onOpen, emptyState, c
           </li>
         ))}
       </ul>
+      {hasMore && onLoadMore && (
+        <button
+          type="button"
+          data-action="knowledge-load-more-objects"
+          onClick={onLoadMore}
+          disabled={loadingMore}
+          className="inline-flex items-center justify-center gap-1.5 self-center rounded-lg border border-border px-3 py-1.5 text-sm text-muted-foreground transition hover:bg-muted disabled:opacity-50"
+        >
+          {loadingMore && <Loader2 className="size-3.5 animate-spin" />}
+          {loadingMore ? "Loading…" : "Load more"}
+        </button>
+      )}
+    </div>
   );
 };
 
@@ -237,28 +255,41 @@ export interface TextReaderProps {
 export const TextReader: FC<TextReaderProps> = ({ outline, readText, highlight, activeSection, className }) => {
   const [slice, setSlice] = useState<TextSlice | null>(null);
   const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [loadingMore, setLoadingMore] = useState(false);
   const markRef = useRef<HTMLSpanElement | null>(null);
+  // Monotonic request id: rapid section/citation nav fires overlapping reads;
+  // only the newest may commit, so a slow earlier response can't clobber it.
+  const reqRef = useRef(0);
 
   const load = useCallback(
     async (sel?: { section?: string; start?: number; end?: number }) => {
+      const req = ++reqRef.current;
       setLoading(true);
+      setError(null);
       try {
-        setSlice(await readText(sel));
+        const next = await readText(sel);
+        if (reqRef.current === req) setSlice(next);
+      } catch {
+        // A failed read must surface, not blank the panel (and never leak as an
+        // unhandled rejection).
+        if (reqRef.current === req) setError("Couldn't load this text. Try again.");
       } finally {
-        setLoading(false);
+        if (reqRef.current === req) setLoading(false);
       }
     },
     [readText],
   );
 
-  // Initial + reactive loads: prefer an explicit highlight span, then an active
+  // Initial + reactive loads: an explicit outline selection wins (so clicking a
-  // section, else the head of the document.
+  // section works even on a citation-opened view), then the highlight span,
+  // else the head of the document.
   useEffect(() => {
-    if (highlight) {
+    if (activeSection) {
+      void load({ section: activeSection });
+    } else if (highlight) {
       const sec = outline.outline.find((s) => highlight.start >= s.start && highlight.end <= s.end);
       void load(sec ? { section: sec.id } : { start: Math.max(0, highlight.start - 200), end: highlight.end + 200 });
-    } else if (activeSection) {
-      void load({ section: activeSection });
     } else {
       void load();
     }
@@ -270,13 +301,20 @@ export const TextReader: FC<TextReaderProps> = ({ outline, readText, highlight,
   }, [slice]);
 
   async function loadMore() {
-    if (!slice?.range) return;
+    if (loadingMore || !slice?.range) return;
+    setLoadingMore(true);
+    try {
       const next = await readText({ start: slice.range.end });
       setSlice((prev) =>
         prev && prev.range && next.range
           ? { ...next, text: (prev.text ?? "") + (next.text ?? ""), range: { start: prev.range.start, end: next.range.end } }
           : next,
       );
+    } catch {
+      setError("Couldn't load more text. Try again.");
+    } finally {
+      setLoadingMore(false);
+    }
   }
 
   if (loading && !slice) {
@@ -286,6 +324,21 @@ export const TextReader: FC<TextReaderProps> = ({ outline, readText, highlight,
       </div>
     );
   }
+  if (error && !slice) {
+    return (
+      <div className={cn("py-8 text-sm", className)}>
+        <p className="text-destructive">{error}</p>
+        <button
+          type="button"
+          data-action="knowledge-text-retry"
+          onClick={() => void load(activeSection ? { section: activeSection } : undefined)}
+          className="mt-2 rounded-lg border border-border px-3 py-1.5 text-sm text-muted-foreground transition hover:bg-muted"
+        >
+          Retry
+        </button>
+      </div>
+    );
+  }
   if (!slice) return null;
 
   const canReadMore = outline.extracted_chars != null && slice.range != null && slice.range.end < outline.extracted_chars;
@@ -295,14 +348,17 @@ export const TextReader: FC<TextReaderProps> = ({ outline, readText, highlight,
       <article className="whitespace-pre-wrap break-words text-sm leading-relaxed text-foreground">
         {renderWithHighlight(slice, highlight, markRef)}
       </article>
+      {error && <p className="mt-2 text-xs text-destructive">{error}</p>}
       {canReadMore && (
         <button
           type="button"
           data-action="knowledge-read-more"
           onClick={() => void loadMore()}
-          className="mt-3 rounded-lg border border-border px-3 py-1.5 text-sm text-muted-foreground transition hover:bg-muted"
+          disabled={loadingMore}
+          className="mt-3 inline-flex items-center gap-1.5 rounded-lg border border-border px-3 py-1.5 text-sm text-muted-foreground transition hover:bg-muted disabled:opacity-50"
         >
-          Read more
+          {loadingMore && <Loader2 className="size-3.5 animate-spin" />}
+          {loadingMore ? "Loading…" : "Read more"}
         </button>
       )}
     </div>
@@ -396,11 +452,23 @@ export const ObjectViewer: FC<ObjectViewerProps> = ({
     !!actions &&
     (actions.onEditMeta || actions.onVerify || actions.onDownload || actions.onArchive || actions.onSupersede || actions.onExtractClaims);
 
+  // Navigating object→object (citation click) reuses this component: clear the
+  // per-object view state so a stale section selection or the previous image
+  // can't bleed into the new object.
+  useEffect(() => {
+    setActiveSection(undefined);
+  }, [outline.object_id]);
+
   useEffect(() => {
     let live = true;
+    setBlob(null);
     if (isImage && outline.has_blob && resolveBlobUrl) {
-      void resolveBlobUrl().then((u) => {
+      void resolveBlobUrl()
+        .then((u) => {
           if (live) setBlob(u);
+        })
+        .catch(() => {
+          /* leave the placeholder frame; the download action still works */
         });
     }
     return () => {