feat(web): FE overhaul — SWR centralized data layer + dashboard + islands

- Add SWR foundation (lib/fetcher, lib/swr, lib/api) with typed
  hooks: useSections/useDocuments/useSearch/useRelated/useRevisions/useQueueStatus
- Replace ad-hoc useEffect+fetch in Header/Sidebar/CommandMenu/search
  with SWR (dedup 4s, focus throttle 10s, debounced search 180ms)
- Doc page: RelatedGrid + RevisionList as SWR client islands (RSC hero stays)
- DocForm: SWR mutate on create/update for live sidebar invalidation
- New APIs: /api/related, /api/revisions, /api/tags, /api/queue/status,
  /api/docs filtering (?section=&status=)
- New UI: DocumentCard, SectionCard, SearchBar, TagCloud, QueueBadge,
  EmptyState, dashboard (/dashboard with QueueStrip live + section stats)
- Layout wraps SWRProvider; no TanStack code (SWR-only per spec)
- Verified: next build passes (16.3.4 Turbopack), no manual fetch sprawl remains

Co-Authored-By: internal-model

apps/web/app/components/RevisionList.tsx

@@ -0,0 +1,68 @@
+"use client";
+
+import { mutate } from "swr";
+import { useRevisions } from "@/hooks/useRevisions";
+import { History } from "lucide-react";
+
+export default function RevisionList({ slug, canEdit }: { slug: string; canEdit: boolean }) {
+  const { revisions, isLoading, error, mutate: revalidate } = useRevisions(slug, 10);
+
+  if (isLoading) {
+    return (
+      <div className="space-y-2 animate-pulse">
+        {Array.from({ length: 3 }).map((_, i) => (
+          <div key={i} className="h-12 bg-[var(--bg-surface)] border border-[var(--border-color)] rounded-lg" />
+        ))}
+      </div>
+    );
+  }
+
+  if (error) {
+    return <p className="text-xs text-amber-600 dark:text-amber-400">Failed to load revisions: {(error as Error).message}</p>;
+  }
+
+  if (revisions.length === 0) return null;
+
+  return (
+    <aside className="mt-10 pt-8 border-t border-[var(--border-color)]">
+      <div className="flex items-center justify-between mb-3.5">
+        <div className="flex items-center gap-2">
+          <History className="w-4 h-4 text-[var(--text-muted)]" />
+          <h2 className="text-xs font-bold text-[var(--text-muted)] uppercase tracking-wider font-mono">Revision History ({revisions.length})</h2>
+        </div>
+      </div>
+      <div className="space-y-2">
+        {revisions.map((rev) => (
+          <div key={rev.id} className="flex items-center justify-between gap-3 p-3 bg-[var(--bg-surface)] border border-[var(--border-color)] rounded-lg text-xs shadow-xs">
+            <div className="flex items-center gap-2 min-w-0 font-mono">
+              <span className="text-[var(--text-primary)] bg-[var(--bg-elevated)] px-1.5 py-0.5 rounded border border-[var(--border-color)] font-bold text-[10px]">v{rev.revisionNo}</span>
+              <span className="text-[var(--text-secondary)] font-sans truncate text-xs">{rev.reason || "Updated document in PostgreSQL"}</span>
+              <span className="text-[var(--text-dim)] hidden sm:inline text-[11px]">· {new Date(rev.createdAt).toLocaleString()}</span>
+            </div>
+            {canEdit && (
+              <form
+                action="/api/revisions/restore"
+                method="post"
+                onSubmit={() => {
+                  // Optimistically revalidate after form post navigates back
+                  setTimeout(() => {
+                    revalidate();
+                    mutate((k) => typeof k === "string" && k.startsWith("/api/docs"));
+                  }, 800);
+                }}
+              >
+                <input type="hidden" name="id" value={rev.id} />
+                <button
+                  type="submit"
+                  className="text-xs text-[var(--text-primary)] hover:text-black dark:hover:text-white bg-[var(--bg-elevated)] hover:bg-[var(--bg-elevated-hover)] px-2.5 py-1 rounded border border-[var(--border-color)] transition-colors font-medium cursor-pointer"
+                >
+                  Restore
+                </button>
+              </form>
+            )}
+          </div>
+        ))}
+      </div>
+    </aside>
+  );
+}