feat: adapt T-HUB features — folders schema, Instagram connector, outreach contacts, media RLS force

From the hacklab/T-HUB fork (diverged at a6843e9):
- 046_file_folders: folder trees (group + personal scope, RLS forced,
  workspace-immutability trigger) + created_by on chat_media_archive
- Instagram connector wired into connect + publishing
- outreach contacts: per-collective DM tracking (todo/sent/replied/declined),
  RLS forced, role-scoped permissions, audit without message text,
  migration renumbered 041→047
- FORCE row-level security on media_assets
The J1 api agent's folder service/controller work continues separately.

apps/web/src/app/(files-host)/files-app/page.tsx

@@ -0,0 +1,9 @@
+import { FilesExplorer } from "../../../components/files/explorer/files-explorer";
+
+/**
+ * Full-screen files experience. files.<domain>/ is rewritten here by
+ * src/middleware.ts; the route also works directly on any host.
+ */
+export default function FilesAppPage(): React.ReactElement {
+  return <FilesExplorer />;
+}