W4: object viewer

components-object: ObjectList, ObjectViewer (CatalogCard + ProvenancePanel +
SupersessionBanner + OutlineNav + TextReader with citation highlight/scroll +
load-more, image render, vault notice, action bar), CitationLink + parseCite.
Demo browses collections → objects → viewer. Typechecks clean.

Co-Authored-By: Claude Fable 5 (build) <noreply@anthropic.com>

demo/knowledge.tsx

@@ -6,18 +6,30 @@ import { useEffect, useState } from "react";
 import {
   CollectionForm,
   CollectionList,
+  ObjectList,
+  ObjectViewer,
   MockKnowledgeTransport,
   type Collection,
   type CollectionInput,
   type CollectionPatch,
   type KnowledgeTransport,
+  type ObjectOutline,
+  type ObjectSummary,
 } from "../src/index";
 
 const transport: KnowledgeTransport = new MockKnowledgeTransport();
 
+type View =
+  | { kind: "collections" }
+  | { kind: "collection"; slug: string }
+  | { kind: "object"; id: string };
+
 export default function KnowledgeDemo() {
+  const [view, setView] = useState<View>({ kind: "collections" });
   const [collections, setCollections] = useState<Collection[]>([]);
   const [pending, setPending] = useState<Record<string, number>>({});
+  const [objects, setObjects] = useState<ObjectSummary[]>([]);
+  const [outline, setOutline] = useState<ObjectOutline | null>(null);
   const [creating, setCreating] = useState<null | "account" | "tenant">(null);
   const [editing, setEditing] = useState<Collection | null>(null);
   const [busy, setBusy] = useState(false);
@@ -35,6 +47,11 @@ export default function KnowledgeDemo() {
     void refresh();
   }, []);
 
+  useEffect(() => {
+    if (view.kind === "collection") void transport.listObjects(view.slug).then((p) => setObjects(p.objects));
+    if (view.kind === "object") void transport.outline(view.id).then(setOutline);
+  }, [view]);
+
   async function onCreate(value: CollectionInput | CollectionPatch) {
     setBusy(true);
     await transport.createCollection(value as CollectionInput);
@@ -42,7 +59,6 @@ export default function KnowledgeDemo() {
     setCreating(null);
     void refresh();
   }
-
   async function onEdit(value: CollectionInput | CollectionPatch) {
     if (!editing) return;
     setBusy(true);
@@ -54,33 +70,61 @@ export default function KnowledgeDemo() {
 
   return (
     <div className="mx-auto max-w-5xl p-6">
-      <header className="mb-6">
+      <button
-        <h1 className="text-xl font-semibold text-foreground">Knowledge</h1>
+        type="button"
-        <p className="text-sm text-muted-foreground">Your corpuses — browse, organise, and review.</p>
+        onClick={() => setView({ kind: "collections" })}
-      </header>
+        className="mb-4 text-sm text-muted-foreground hover:text-foreground"
+      >
+        Knowledge{view.kind !== "collections" ? " / …" : ""}
+      </button>
 
+      {view.kind === "collections" && (
+        <>
           {creating && (
             <div className="mb-6 rounded-xl border border-border bg-card p-4">
               <h2 className="mb-3 font-medium">New corpus</h2>
               <CollectionForm mode="create" ownerType={creating} orgName="Acme" canManageTenant busy={busy} onSubmit={onCreate} onCancel={() => setCreating(null)} />
             </div>
           )}
-
           {editing && (
             <div className="mb-6 rounded-xl border border-border bg-card p-4">
               <h2 className="mb-3 font-medium">Corpus settings</h2>
               <CollectionForm mode="edit" initial={editing} orgName="Acme" canManageTenant busy={busy} onSubmit={onEdit} onCancel={() => setEditing(null)} />
             </div>
           )}
-
           <CollectionList
             collections={collections}
             pendingCounts={pending}
             orgName="Acme"
             canManageTenant
             onCreate={(owner) => setCreating(owner)}
-        onOpen={(c) => setEditing(c)}
+            onOpen={(c) => setView({ kind: "collection", slug: c.slug })}
           />
+        </>
+      )}
+
+      {view.kind === "collection" && (
+        <>
+          <div className="mb-3 flex items-center justify-between">
+            <h1 className="text-lg font-semibold">{view.slug}</h1>
+            <button className="text-sm text-primary" onClick={() => setEditing(collections.find((c) => c.slug === view.slug) ?? null)}>Settings</button>
+          </div>
+          <ObjectList objects={objects} onOpen={(o) => setView({ kind: "object", id: o.object_id })} />
+        </>
+      )}
+
+      {view.kind === "object" && outline && (
+        <ObjectViewer
+          outline={outline}
+          readText={(sel) => transport.readText(outline.object_id, sel)}
+          resolveBlobUrl={() => transport.blobUrl(outline.object_id)}
+          onOpenObject={(id) => setView({ kind: "object", id })}
+          actions={{
+            onVerify: () => transport.updateObject(outline.object_id, { verified_at: new Date().toISOString() }),
+            onDownload: () => transport.blobUrl(outline.object_id).then((u) => window.open(u)),
+          }}
+        />
+      )}
     </div>
   );
 }

src/components-object.tsx

@@ -1,2 +1,470 @@
-// Placeholder — filled in its workstream (W4/W5/W6).
+// PURPOSE: Object viewer (spec §3.4) — catalog card + provenance + supersession
-export {};
+//          + outline-driven text reader with citation highlighting, image render,
+//          vault notice, and object actions. Plus ObjectList + CitationLink.
+//          Pure: text is loaded via an injected readText callback, not fetched.
+// ===========================================================================
+import { useCallback, useEffect, useRef, useState, type FC, type ReactNode, type RefObject } from "react";
+import {
+  ArrowUpRight,
+  Check,
+  Download,
+  FileText,
+  Image as ImageIcon,
+  Loader2,
+  Lock,
+  Sparkles,
+  Tag,
+  Trash2,
+} from "lucide-react";
+import type { ObjectOutline, ObjectSummary, OutlineSection, TextSlice } from "./types";
+import {
+  Badge,
+  SensitivityBadge,
+  StatusBadge,
+  cn,
+  formatBytes,
+  formatDate,
+  isImageMime,
+} from "./_internal";
+
+// ---- ObjectList -----------------------------------------------------------
+
+export interface ObjectListProps {
+  objects: ObjectSummary[];
+  onOpen?: (object: ObjectSummary) => void;
+  emptyState?: ReactNode;
+  className?: string;
+}
+
+export const ObjectList: FC<ObjectListProps> = ({ objects, onOpen, 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)}>
+      {objects.map((o) => (
+        <li key={o.object_id}>
+          <button
+            type="button"
+            data-action="knowledge-open-object"
+            data-object-id={o.object_id}
+            onClick={() => onOpen?.(o)}
+            className="flex w-full items-center gap-3 px-4 py-3 text-left transition hover:bg-muted/50 focus:outline-none focus-visible:bg-muted/50"
+          >
+            <span className="text-muted-foreground">{o.kind === "claim" ? <Sparkles className="size-4" /> : <FileText className="size-4" />}</span>
+            <span className="min-w-0 flex-1">
+              <span className={cn("block truncate text-sm font-medium", o.status === "superseded" && "text-muted-foreground line-through")}>{o.title}</span>
+              <span className="text-xs text-muted-foreground">{o.effective_at ? `effective ${formatDate(o.effective_at)}` : `updated ${formatDate(o.updated_at)}`}</span>
+            </span>
+            <StatusBadge status={o.status} />
+            <SensitivityBadge level={o.sensitivity} />
+          </button>
+        </li>
+      ))}
+    </ul>
+  );
+};
+
+// ---- CitationLink ---------------------------------------------------------
+
+export function parseCite(cite: string): { objectId: string; span?: { start: number; end: number } } | null {
+  const m = /^kb:\/\/([^#]+)(?:#(\d+)-(\d+))?$/.exec(cite);
+  if (!m) return null;
+  return { objectId: m[1], span: m[2] ? { start: Number(m[2]), end: Number(m[3]) } : undefined };
+}
+
+/** Renders a `kb://<id>#s-e` handle as a click-through the app routes to the
+ *  object viewer with ?start=&end=. `onOpen` receives (objectId, span). */
+export interface CitationLinkProps {
+  cite: string;
+  label?: string;
+  onOpen?: (objectId: string, span?: { start: number; end: number }) => void;
+  className?: string;
+}
+
+export const CitationLink: FC<CitationLinkProps> = ({ cite, label, onOpen, className }) => {
+  const parsed = parseCite(cite);
+  return (
+    <button
+      type="button"
+      data-action="knowledge-citation"
+      onClick={() => parsed && onOpen?.(parsed.objectId, parsed.span)}
+      className={cn(
+        "inline-flex max-w-full items-center gap-1 rounded-md bg-muted px-1.5 py-0.5 font-mono text-xs text-muted-foreground transition hover:text-foreground",
+        className,
+      )}
+      title={cite}
+    >
+      <span className="truncate">{label ?? cite}</span>
+      <ArrowUpRight className="size-3 shrink-0" />
+    </button>
+  );
+};
+
+// ---- CatalogCard ----------------------------------------------------------
+
+export const CatalogCard: FC<{ outline: ObjectOutline; className?: string }> = ({ outline, className }) => (
+  <div className={cn("flex flex-col gap-3", className)}>
+    <div className="flex flex-wrap items-center gap-1.5">
+      <StatusBadge status={outline.status} />
+      <SensitivityBadge level={outline.sensitivity} />
+      {outline.language && <Badge tone="bg-muted text-muted-foreground">{outline.language.toUpperCase()}</Badge>}
+      {outline.mime && <Badge tone="bg-muted text-muted-foreground">{outline.mime}</Badge>}
+      {outline.byte_size != null && <span className="text-xs text-muted-foreground">{formatBytes(outline.byte_size)}</span>}
+    </div>
+    <h1 className="text-lg font-semibold text-foreground">{outline.title}</h1>
+    {outline.summary && <p className="text-sm leading-relaxed text-muted-foreground">{outline.summary}</p>}
+    {(outline.tags.length > 0 || outline.entities.length > 0) && (
+      <div className="flex flex-wrap gap-1.5">
+        {outline.tags.map((t) => (
+          <Badge key={t} tone="bg-muted text-muted-foreground" icon={<Tag className="size-3" />}>
+            {t}
+          </Badge>
+        ))}
+        {outline.entities.map((e) => (
+          <Badge key={e.name} tone="bg-primary/10 text-primary" title={e.type}>
+            {e.name}
+          </Badge>
+        ))}
+      </div>
+    )}
+  </div>
+);
+
+// ---- ProvenancePanel ------------------------------------------------------
+
+export const ProvenancePanel: FC<{ outline: ObjectOutline; className?: string }> = ({ outline, className }) => {
+  const p = outline.provenance;
+  const rows: [string, ReactNode][] = [
+    ["Source", p.source_ref ? `${p.source_type} · ${p.source_ref}` : p.source_type],
+    ["Added by", p.created_by ?? "—"],
+    ["Added", formatDate(p.inserted_at)],
+    ["Effective", p.effective_at ? formatDate(p.effective_at) : "—"],
+    ["Last verified", p.verified_at ? formatDate(p.verified_at) : "Not confirmed"],
+    ["Card model", p.card_model ?? "— (mechanical)"],
+    ["Extraction model", p.extraction_model ?? "— (native text)"],
+  ];
+  return (
+    <div className={cn("rounded-xl border border-border bg-card p-4", className)}>
+      <h3 className="mb-3 text-sm font-semibold text-foreground">Provenance</h3>
+      <dl className="grid grid-cols-[auto_1fr] gap-x-4 gap-y-1.5 text-sm">
+        {rows.map(([k, v]) => (
+          <div key={k} className="contents">
+            <dt className="text-muted-foreground">{k}</dt>
+            <dd className="break-words text-foreground">{v}</dd>
+          </div>
+        ))}
+      </dl>
+    </div>
+  );
+};
+
+// ---- SupersessionBanner ---------------------------------------------------
+
+export const SupersessionBanner: FC<{
+  outline: ObjectOutline;
+  onOpen?: (objectId: string) => void;
+  className?: string;
+}> = ({ outline, onOpen, className }) => {
+  if (!outline.superseded_by && !outline.supersedes) return null;
+  return (
+    <div className={cn("flex flex-col gap-2", className)}>
+      {outline.superseded_by && (
+        <div className="flex items-center gap-2 rounded-lg border border-[var(--warning)]/40 bg-[color-mix(in_oklab,var(--warning)_10%,transparent)] px-3 py-2 text-sm">
+          <span className="text-[var(--warning)]">A newer version of this document exists.</span>
+          <button
+            type="button"
+            data-action="knowledge-open-newer"
+            onClick={() => onOpen?.(outline.superseded_by!)}
+            className="ml-auto inline-flex items-center gap-1 font-medium text-primary hover:underline"
+          >
+            Open newer <ArrowUpRight className="size-3.5" />
+          </button>
+        </div>
+      )}
+      {outline.supersedes && (
+        <button
+          type="button"
+          onClick={() => onOpen?.(outline.supersedes!)}
+          className="inline-flex items-center gap-1 self-start text-xs text-muted-foreground hover:text-foreground"
+        >
+          Replaces an earlier version <ArrowUpRight className="size-3" />
+        </button>
+      )}
+    </div>
+  );
+};
+
+// ---- OutlineNav -----------------------------------------------------------
+
+export const OutlineNav: FC<{
+  sections: OutlineSection[];
+  activeId?: string;
+  onSelect?: (section: OutlineSection) => void;
+  className?: string;
+}> = ({ sections, activeId, onSelect, className }) => {
+  if (sections.length === 0) return null;
+  return (
+    <nav className={cn("flex flex-col gap-0.5", className)} aria-label="Document outline">
+      {sections.map((s) => (
+        <button
+          key={s.id}
+          type="button"
+          data-action="knowledge-outline-section"
+          onClick={() => onSelect?.(s)}
+          className={cn(
+            "truncate rounded-md px-2 py-1 text-left text-sm transition hover:bg-muted",
+            s.level > 1 && "pl-4 text-xs",
+            activeId === s.id ? "bg-muted font-medium text-foreground" : "text-muted-foreground",
+          )}
+        >
+          {s.heading}
+        </button>
+      ))}
+    </nav>
+  );
+};
+
+// ---- TextReader -----------------------------------------------------------
+
+export interface TextReaderProps {
+  outline: ObjectOutline;
+  readText: (sel?: { section?: string; start?: number; end?: number }) => Promise<TextSlice>;
+  /** A span to load, mark, and scroll to (citation resolver, spec §3.4). */
+  highlight?: { start: number; end: number };
+  activeSection?: string;
+  className?: string;
+}
+
+export const TextReader: FC<TextReaderProps> = ({ outline, readText, highlight, activeSection, className }) => {
+  const [slice, setSlice] = useState<TextSlice | null>(null);
+  const [loading, setLoading] = useState(false);
+  const markRef = useRef<HTMLSpanElement | null>(null);
+
+  const load = useCallback(
+    async (sel?: { section?: string; start?: number; end?: number }) => {
+      setLoading(true);
+      try {
+        setSlice(await readText(sel));
+      } finally {
+        setLoading(false);
+      }
+    },
+    [readText],
+  );
+
+  // Initial + reactive loads: prefer an explicit highlight span, then an active
+  // section, else the head of the document.
+  useEffect(() => {
+    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();
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [highlight?.start, highlight?.end, activeSection, outline.object_id]);
+
+  useEffect(() => {
+    if (markRef.current) markRef.current.scrollIntoView({ block: "center", behavior: "smooth" });
+  }, [slice]);
+
+  async function loadMore() {
+    if (!slice?.range) return;
+    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,
+    );
+  }
+
+  if (loading && !slice) {
+    return (
+      <div className={cn("flex items-center gap-2 py-8 text-sm text-muted-foreground", className)}>
+        <Loader2 className="size-4 animate-spin" /> Loading…
+      </div>
+    );
+  }
+  if (!slice) return null;
+
+  const canReadMore = outline.extracted_chars != null && slice.range != null && slice.range.end < outline.extracted_chars;
+
+  return (
+    <div className={className}>
+      <article className="whitespace-pre-wrap break-words text-sm leading-relaxed text-foreground">
+        {renderWithHighlight(slice, highlight, markRef)}
+      </article>
+      {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"
+        >
+          Read more
+        </button>
+      )}
+    </div>
+  );
+};
+
+function renderWithHighlight(
+  slice: TextSlice,
+  highlight: { start: number; end: number } | undefined,
+  markRef: RefObject<HTMLSpanElement | null>,
+): ReactNode {
+  const text = slice.text ?? "";
+  const base = slice.range?.start ?? 0;
+  if (!highlight) return text;
+  const from = highlight.start - base;
+  const to = highlight.end - base;
+  if (from < 0 || from >= text.length || to <= from) return text;
+  return (
+    <>
+      {text.slice(0, from)}
+      <span ref={markRef} className="rounded bg-[color-mix(in_oklab,var(--warning)_28%,transparent)] px-0.5">
+        {text.slice(from, to)}
+      </span>
+      {text.slice(to)}
+    </>
+  );
+}
+
+// ---- ObjectActions --------------------------------------------------------
+
+export interface ObjectActions {
+  onEditMeta?: () => void;
+  onVerify?: () => void;
+  onArchive?: () => void;
+  onDownload?: () => void;
+  onSupersede?: () => void;
+  onExtractClaims?: () => void;
+}
+
+const ActionButton: FC<{ onClick?: () => void; icon: ReactNode; children: ReactNode; action: string; danger?: boolean }> = ({
+  onClick,
+  icon,
+  children,
+  action,
+  danger,
+}) =>
+  onClick ? (
+    <button
+      type="button"
+      data-action={action}
+      onClick={onClick}
+      className={cn(
+        "inline-flex items-center gap-1.5 rounded-lg border px-2.5 py-1.5 text-xs font-medium transition",
+        danger
+          ? "border-destructive/30 text-destructive hover:bg-destructive/10"
+          : "border-border text-muted-foreground hover:bg-muted hover:text-foreground",
+      )}
+    >
+      {icon}
+      {children}
+    </button>
+  ) : null;
+
+// ---- ObjectViewer (composite) --------------------------------------------
+
+export interface ObjectViewerProps {
+  outline: ObjectOutline;
+  readText: TextReaderProps["readText"];
+  /** Resolve a browser-openable blob URL (for images + download). */
+  resolveBlobUrl?: () => Promise<string>;
+  highlight?: { start: number; end: number };
+  onOpenObject?: (objectId: string, span?: { start: number; end: number }) => void;
+  actions?: ObjectActions;
+  className?: string;
+}
+
+export const ObjectViewer: FC<ObjectViewerProps> = ({
+  outline,
+  readText,
+  resolveBlobUrl,
+  highlight,
+  onOpenObject,
+  actions,
+  className,
+}) => {
+  const [activeSection, setActiveSection] = useState<string | undefined>();
+  const [blob, setBlob] = useState<string | null>(null);
+  const isImage = isImageMime(outline.mime);
+  const isVault = outline.sensitivity === "vault";
+  const hasActions =
+    !!actions &&
+    (actions.onEditMeta || actions.onVerify || actions.onDownload || actions.onArchive || actions.onSupersede || actions.onExtractClaims);
+
+  useEffect(() => {
+    let live = true;
+    if (isImage && outline.has_blob && resolveBlobUrl) {
+      void resolveBlobUrl().then((u) => {
+        if (live) setBlob(u);
+      });
+    }
+    return () => {
+      live = false;
+    };
+  }, [isImage, outline.has_blob, outline.object_id, resolveBlobUrl]);
+
+  return (
+    <div className={cn("flex flex-col gap-5", className)}>
+      <SupersessionBanner outline={outline} onOpen={onOpenObject} />
+      <CatalogCard outline={outline} />
+
+      {hasActions && (
+        <div className="flex flex-wrap gap-2">
+          <ActionButton action="knowledge-edit-meta" onClick={actions?.onEditMeta} icon={<Tag className="size-3.5" />}>Edit title &amp; tags</ActionButton>
+          <ActionButton action="knowledge-verify" onClick={actions?.onVerify} icon={<Check className="size-3.5" />}>Confirm still current</ActionButton>
+          {outline.has_blob && <ActionButton action="knowledge-download" onClick={actions?.onDownload} icon={<Download className="size-3.5" />}>Download original</ActionButton>}
+          <ActionButton action="knowledge-supersede" onClick={actions?.onSupersede} icon={<ArrowUpRight className="size-3.5" />}>Replace with newer</ActionButton>
+          {!isVault && <ActionButton action="knowledge-extract-claims" onClick={actions?.onExtractClaims} icon={<Sparkles className="size-3.5" />}>Extract claims</ActionButton>}
+          <ActionButton action="knowledge-archive" onClick={actions?.onArchive} icon={<Trash2 className="size-3.5" />} danger>Archive</ActionButton>
+        </div>
+      )}
+
+      {isVault && (
+        <div className="flex items-start gap-2 rounded-lg border border-destructive/30 bg-[color-mix(in_oklab,var(--destructive)_8%,transparent)] px-3 py-2 text-sm">
+          <Lock className="mt-0.5 size-4 shrink-0 text-destructive" />
+          <span className="text-foreground">
+            <span className="font-medium">Vault.</span> Never sent to AI models — the catalog is file metadata only. You can still read and download it here.
+          </span>
+        </div>
+      )}
+
+      {isImage && outline.has_blob && (
+        <figure className="overflow-hidden rounded-xl border border-border bg-muted/30">
+          {blob ? (
+            <img src={blob} alt={outline.title} className="max-h-[480px] w-full object-contain" />
+          ) : (
+            <div className="flex h-40 items-center justify-center text-muted-foreground">
+              <ImageIcon className="size-6" />
+            </div>
+          )}
+        </figure>
+      )}
+
+      <div className="grid gap-5 lg:grid-cols-[1fr_260px]">
+        <div className="min-w-0 rounded-xl border border-border bg-card p-4">
+          {outline.extracted_chars && outline.extracted_chars > 0 ? (
+            <TextReader outline={outline} readText={readText} highlight={highlight} activeSection={activeSection} />
+          ) : (
+            <p className="text-sm text-muted-foreground">
+              {isImage ? "This image's description is its searchable text — see the summary above." : "No extracted text for this object."}
+            </p>
+          )}
+        </div>
+        <aside className="flex flex-col gap-4">
+          {outline.outline.length > 0 && (
+            <div className="rounded-xl border border-border bg-card p-3">
+              <h3 className="mb-2 px-2 text-xs font-semibold uppercase tracking-wide text-muted-foreground">Outline</h3>
+              <OutlineNav sections={outline.outline} activeId={activeSection} onSelect={(s) => setActiveSection(s.id)} />
+            </div>
+          )}
+          <ProvenancePanel outline={outline} />
+        </aside>
+      </div>
+    </div>
+  );
+};