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/layout/sidebar.tsx

@@ -23,6 +23,7 @@ import {
   Sparkles,
   Building2,
   Radio,
+  Share2,
 } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import { ScrollArea } from "@/components/ui/scroll-area";
@@ -32,6 +33,7 @@ export const navItems = [
   // Dashboard
   { title: "Overview", href: "/overview", icon: LayoutDashboard },
   { title: "Business", href: "/business", icon: Building2 },
+  { title: "Social", href: "/social", icon: Share2 },
 
   // Work Management
   { title: "Tasks", href: "/tasks", icon: ListTodo },