feat: status popover + CSV export

Two follow-ons after the ⌘K palette:

StatusIndicator → Popover
- The top-bar status light is no longer a direct link to /status.
  Clicking it opens a popover with grouped issues (failing
  integrations, expired tokens, expiring tokens) so a quick glance
  answers "what's broken" without leaving the current page.  A "View
  full status" link at the bottom routes to /status when needed.
- The trigger keeps the same color rollup so the visual hint is
  visible without opening the popover.

DataTable → CSV export
- Optional `exportable` + `exportFilename` props add an "Export CSV"
  button next to the search bar.  Default behavior exports the current
  page; pass `onExportAll` for server-side full-result downloads.
- Built client-side from column defs (label → header, raw value →
  cell).  BOM-prefixed UTF-8 so Excel decodes correctly.  Quoting +
  escape handled.
- Enabled on /admin/data-browser/{companies,tickets} as initial demos.
  Other data-browser pages opt in by adding two props.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/admin/data-browser/tickets/page.tsx

@@ -171,6 +171,8 @@ export default function TicketsBrowserPage() {
             onSearch={(query) => fetchTickets(1, query)}
             onRowClick={handleRowClick}
             isLoading={isLoading}
+            exportable
+            exportFilename="tickets"
           />
         </CardContent>
       </Card>