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/api-server/tests/executive-meetings.test.mjs

@@ -663,6 +663,28 @@ test("Reorder: POST /reorder renumbers a full day to 1..N and inherits slot time
     "audit new_value.order must echo the new ordering");
 });
 
+test("Reorder: rejects orderedIds containing duplicates with code duplicate_ids", async () => {
+  // Even though full-day membership would otherwise be satisfied, sending the
+  // same id twice must be refused so we never assign the same dailyNumber to
+  // two distinct rows during the two-phase renumber.
+  const reorderDate = "2050-04-04";
+  const a = await api(adminCookie, "POST", "/api/executive-meetings", {
+    titleAr: "أ", titleEn: "A", meetingDate: reorderDate,
+  });
+  const A = await a.json(); created.meetingIds.push(A.id);
+  const b = await api(adminCookie, "POST", "/api/executive-meetings", {
+    titleAr: "ب", titleEn: "B", meetingDate: reorderDate,
+  });
+  const B = await b.json(); created.meetingIds.push(B.id);
+  const r = await api(adminCookie, "POST",
+    "/api/executive-meetings/reorder",
+    { meetingDate: reorderDate, orderedIds: [A.id, A.id, B.id] });
+  assert.equal(r.status, 400);
+  const body = await r.json();
+  assert.equal(body.code, "duplicate_ids",
+    "duplicate ids must be reported with the duplicate_ids code");
+});
+
 test("Reorder: rejects an incomplete-day request (orderedIds missing some)", async () => {
   const reorderDate = "2050-02-20";
   const a = await api(adminCookie, "POST", "/api/executive-meetings", {