Task #733: dark outline around expanded booking + its details; removed "اسم الاجتماع" label

- protocol.tsx renderBookingRow: when expanded, the booking row gets
  border-2 border-b-0 border-slate-500 and the details row gets
  !border-2 !border-t-0 !border-slate-500 — one continuous dark frame
  around the whole block. Important modifiers on the details row defeat
  TableBody's [&_tr:last-child]:border-0 reset so the frame survives when
  the expanded booking is the last row (architect review fix). Removed the
  old inner border-b slate-400 on the details container.
- Details card header: removed the small "اسم الاجتماع" label span; only
  the meeting title (b.title, centered, bold) remains.
- Deleted the now-unused protocol.bookings.table.title key from ar.json
  and en.json (verified no remaining usages, JSON parses).
- UI-only; tsc --noEmit clean.

artifacts/tx-os/src/locales/ar.json

@@ -1811,7 +1811,6 @@
       "linkCopied": "تم نسخ الرابط",
       "linkCopyFailed": "تعذّر نسخ الرابط",
       "table": {
-        "title": "اسم الاجتماع",
         "number": "رقم الحجز",
         "requester": "مقدم الطلب",
         "date": "تاريخ الحجز",