feat: Social page — aggregated post queues + X/video history (#345)

* feat(api): x/video post history endpoints

Approved or rejected drafts vanished from both queues permanently --
the listers exclude terminal statuses and no history surface existed,
so a posted tweet or video was only findable in the raw task list.
GET /x/posts/history and GET /video/posts/history (CEO-gated, bounded)
return acted-on drafts newest-first with the posted platform ids and
reject reasons from the draft markers. Route tests assert by identity,
not emptiness: approve/reject commits the whole session, so prior
tests' rows legitimately persist in the shared test DB.

* feat(panel): Social page aggregating post queues and history

New dashboard page composing the X and video post queues with one
unified history section beneath them -- both platforms interleaved
newest-first, kind and outcome badges, posted X ids linking to the
live tweet, reject reasons shown. The command center's two full queue
cards become a compact pending-counts card linking to the page, so the
queues have one home instead of duplicated surfaces.

---------

Co-authored-by: Renn F <rennf93@users.noreply.github.com>

panel/src/components/dashboard/x-post-queue.tsx

@@ -125,7 +125,8 @@ function XPostRow({
 }
 
 // CEO queue for held X drafts (release posts + mention replies). Hidden when
-// empty (mirrors the release-proposal + playbook-review queues).
+// empty (mirrors the release-proposal + playbook-review queues). Posted/
+// rejected drafts move to the unified history on /social (SocialHistorySection).
 export function XPostQueue({ className }: { className?: string }) {
   const queryClient = useQueryClient();
   const [rejecting, setRejecting] = useState<XPost | null>(null);
@@ -197,13 +198,12 @@ export function XPostQueue({ className }: { className?: string }) {
       <Card className={className}>
         <CardHeader>
           <CardTitle className="flex items-center gap-2">
-            <Rocket className="h-5 w-5" />
-            X Post Queue
+            <Rocket className="h-5 w-5" />X Post Queue
           </CardTitle>
           <CardDescription>
             Drafted release announcements, feature spotlights, and mention
-            replies (if enabled) land here for you to edit, approve, or
-            reject. Nothing posts on its own.
+            replies (if enabled) land here for you to edit, approve, or reject.
+            Nothing posts on its own.
           </CardDescription>
         </CardHeader>
         <CardContent>
@@ -222,8 +222,7 @@ export function XPostQueue({ className }: { className?: string }) {
       <Card className={className}>
         <CardHeader>
           <CardTitle className="flex items-center gap-2">
-            <Rocket className="h-5 w-5" />
-            X Post Queue
+            <Rocket className="h-5 w-5" />X Post Queue
             <Badge variant="secondary">{posts.length}</Badge>
           </CardTitle>
           <CardDescription>