Executive Meetings: inline editing, drag reorder, and current-meeting highlight

Implements Task #122 — four features on the Executive Meetings schedule:
1. Word-like inline editing of meeting title and attendee names with bold,
   italic, underline, color, font-family, font-size, and text-align controls
   (Tiptap-backed EditableCell + FormattingToolbar).
2. Drag-to-reorder column headers (dnd-kit), persisted in the existing
   em-schedule-cols-v1 storage key. Old up/down buttons removed.
3. Drag-to-reorder rows within a day. New POST /api/executive-meetings/reorder
   endpoint permutes daily_number + start/end times in a single transaction
   using a two-phase negative→final assignment that respects the
   (date, daily_number) UNIQUE constraint and survives partial-day reorders.
   Audit-logged and role-guarded.
4. Highlight the meeting whose start/end window is "now", refreshed every
   60 s. Toggle and color picker live in the customize popover and persist
   to localStorage (em-current-meeting-highlight-v1).

Backend changes
- Widened titleAr / titleEn / attendees.name to text.
- New artifacts/api-server/src/lib/sanitize.ts with an allowlist for
  inline tags + safe inline styles. Applied to POST, PATCH, PUT-attendees,
  duplicate, reorder, and applyApprovedRequest (add_attendee) paths so
  rich text round-trips safely.
- Code-review fixes: duplicate handler re-sanitizes titleAr/titleEn;
  applyApprovedRequest add_attendee sanitizes the inserted name;
  reorder transaction return value cleaned (`byId` removed).
- 5 new tests cover sanitization stripping, reorder happy path, cross-day
  rejection, permission denial, and applyApprovedRequest sanitization.
  Pre-existing app_permissions failures are unrelated (tracked by #126/#127).

Frontend changes
- artifacts/tx-os/src/components/editable-cell.tsx with FormattingToolbar
  (custom FontSize Tiptap extension + @tiptap/extension-text-align).
- ScheduleSection wires saveTitle, saveAttendeeName, reorder mutation
  (optimistic with revert on error), highlight tick, and HighlightPrefs.
- New SortableHeader component for column drag.
- AttendeesCell passes the original attendee index to PUT writes so edits
  reach the right row even after grouping into virtual/internal/external.
- Print page renders sanitized rich text via dangerouslySetInnerHTML on
  names and titles; attendee.title is rendered as a plain text node (XSS).
- Translation keys added in ar.json and en.json.

artifacts/tx-os/src/pages/executive-meetings.tsx

@@ -746,6 +746,7 @@ function ScheduleSection({
   // server round-trip finishes. Cleared on each new meetings prop.
   const [optimisticOrder, setOptimisticOrder] = useState<number[] | null>(null);
   const [reordering, setReordering] = useState(false);
+  const reorderingRef = useRef(false);
   useEffect(() => {
     setOptimisticOrder(null);
   }, [meetings, date]);
@@ -827,6 +828,7 @@ function ScheduleSection({
   const reorderRows = useCallback(
     async (fromId: number, toId: number) => {
       if (fromId === toId) return;
+      if (reorderingRef.current) return;
       const ids = meetings.map((m) => m.id);
       const fromIdx = ids.indexOf(fromId);
       const toIdx = ids.indexOf(toId);
@@ -835,6 +837,7 @@ function ScheduleSection({
       newOrder.splice(fromIdx, 1);
       newOrder.splice(toIdx, 0, fromId);
       setOptimisticOrder(newOrder);
+      reorderingRef.current = true;
       setReordering(true);
       try {
         await apiJson(`/api/executive-meetings/reorder`, {
@@ -851,6 +854,7 @@ function ScheduleSection({
           variant: "destructive",
         });
       } finally {
+        reorderingRef.current = false;
         setReordering(false);
       }
     },