Task #666: Today & Book buttons in room-booking calendar view

Added two quick actions inside the Protocol bookings "Calendar" view's day
panel header (artifacts/tx-os/src/pages/protocol.tsx):
- "Today" (اليوم): outline button that resets selectedDay to new Date(), so
  the month picker, day time-grid, and red now-line all snap to today.
- "Book" (حجز): primary button gated by the same c?.canRequest capability as
  the existing toolbar new-booking button. Opens the new-booking dialog
  pre-filled with the currently selected day.

Implementation:
- Extended bookingDialog state with an optional `day?: Date`.
- BookingDialog now accepts an `initialDay?: Date` prop; for new (non-edit)
  bookings it pre-fills startsAt=09:00 and endsAt=10:00 on that day via a
  local dayAt(hour) helper (reuses toLocalInput). Edit flow unchanged.
- Added i18n keys protocol.bookings.today / protocol.bookings.book to both
  ar.json and en.json. Buttons use logical spacing (me-1) so they mirror in
  Arabic RTL.

No backend/API changes. List/Calendar toggle unaffected. tx-os typecheck
passes; HMR clean, no console errors. Screenshot tool unavailable (no
artifact registered in this repo), verified via typecheck + logs.

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

@@ -1723,6 +1723,8 @@
       "endsAt": "إلى",
       "viewList": "قائمة",
       "viewCalendar": "تقويم",
+      "today": "اليوم",
+      "book": "حجز",
       "emptyDay": "لا توجد حجوزات في هذا اليوم.",
       "shareLinkTitle": "رابط الحجز العام (للمشاركة مع الضيوف)",
       "copyLink": "نسخ الرابط",

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

@@ -1596,6 +1596,8 @@
       "endsAt": "To",
       "viewList": "List",
       "viewCalendar": "Calendar",
+      "today": "Today",
+      "book": "Book",
       "emptyDay": "No bookings on this day.",
       "shareLinkTitle": "Public booking link (share with guests)",
       "copyLink": "Copy link",

artifacts/tx-os/src/pages/protocol.tsx

@@ -556,6 +556,7 @@ export default function ProtocolPage() {
   const [bookingDialog, setBookingDialog] = useState<{
     open: boolean;
     edit?: Booking;
+    day?: Date;
   }>({ open: false });
   const [rejectTarget, setRejectTarget] = useState<{
     kind: "booking" | "issue" | "external";
@@ -978,13 +979,36 @@ export default function ProtocolPage() {
                   </div>
                 </div>
                 <div className="min-w-0 flex-1 rounded-xl border border-slate-200 bg-white p-3">
-                  <div className="mb-3 text-sm font-semibold text-slate-600">
-                    {selectedDay.toLocaleDateString(isAr ? "ar" : "en", {
-                      weekday: "long",
-                      year: "numeric",
-                      month: "long",
-                      day: "numeric",
-                    })}
+                  <div className="mb-3 flex flex-wrap items-center justify-between gap-2">
+                    <div className="text-sm font-semibold text-slate-600">
+                      {selectedDay.toLocaleDateString(isAr ? "ar" : "en", {
+                        weekday: "long",
+                        year: "numeric",
+                        month: "long",
+                        day: "numeric",
+                      })}
+                    </div>
+                    <div className="flex items-center gap-2">
+                      <Button
+                        size="sm"
+                        variant="outline"
+                        onClick={() => setSelectedDay(new Date())}
+                      >
+                        <CalendarDays size={14} className="me-1" />
+                        {t("protocol.bookings.today")}
+                      </Button>
+                      {c?.canRequest && (
+                        <Button
+                          size="sm"
+                          onClick={() =>
+                            setBookingDialog({ open: true, day: selectedDay })
+                          }
+                        >
+                          <Plus size={14} className="me-1" />
+                          {t("protocol.bookings.book")}
+                        </Button>
+                      )}
+                    </div>
                   </div>
                   <div className="max-h-[70vh] overflow-y-auto">
                     <BookingDayGrid
@@ -1364,6 +1388,7 @@ export default function ProtocolPage() {
         <BookingDialog
           rooms={rooms.data ?? []}
           edit={bookingDialog.edit}
+          initialDay={bookingDialog.day}
           nameOf={nameOf}
           onClose={() => setBookingDialog({ open: false })}
           onSaved={() => {
@@ -1709,6 +1734,7 @@ function DialogShell({
 function BookingDialog({
   rooms,
   edit,
+  initialDay,
   nameOf,
   onClose,
   onSaved,
@@ -1716,21 +1742,30 @@ function BookingDialog({
 }: {
   rooms: Room[];
   edit?: Booking;
+  initialDay?: Date;
   nameOf: (ar: string, en: string) => string;
   onClose: () => void;
   onSaved: () => void;
   onError: (e: unknown) => void;
 }) {
   const { t } = useTranslation();
+  const dayAt = (hour: number) => {
+    if (!initialDay) return "";
+    const d = new Date(initialDay);
+    d.setHours(hour, 0, 0, 0);
+    return toLocalInput(d.toISOString());
+  };
   const [title, setTitle] = useState(edit?.title ?? "");
   const [roomId, setRoomId] = useState<string>(
     edit ? String(edit.roomId) : rooms[0] ? String(rooms[0].id) : "",
   );
   const [requesterName, setRequesterName] = useState(edit?.requesterName ?? "");
   const [startsAt, setStartsAt] = useState(
-    edit ? toLocalInput(edit.startsAt) : "",
+    edit ? toLocalInput(edit.startsAt) : dayAt(9),
+  );
+  const [endsAt, setEndsAt] = useState(
+    edit ? toLocalInput(edit.endsAt) : dayAt(10),
   );
-  const [endsAt, setEndsAt] = useState(edit ? toLocalInput(edit.endsAt) : "");
   const [notes, setNotes] = useState(edit?.notes ?? "");
 
   const mut = useMutation({