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/locales/ar.json

@@ -753,7 +753,8 @@
     },
     "highlight": {
       "title": "تمييز الاجتماع الحالي",
-      "hint": "تظليل الاجتماع الذي يقع وقته الآن."
+      "hint": "تظليل الاجتماع الذي يقع وقته الآن.",
+      "reset": "إعادة إلى الافتراضي"
     },
     "dragRow": "اسحب لإعادة الترتيب",
     "editMeetingTitle": "تعديل عنوان الاجتماع",

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

@@ -706,7 +706,8 @@
     },
     "highlight": {
       "title": "Highlight current meeting",
-      "hint": "Outline the meeting whose time is now."
+      "hint": "Outline the meeting whose time is now.",
+      "reset": "Reset to default"
     },
     "dragRow": "Drag to reorder",
     "editMeetingTitle": "Edit meeting title",

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

@@ -1274,7 +1274,7 @@ function ColumnsCustomizer({
           <p className="text-[11px] text-muted-foreground mb-2 leading-relaxed">
             {t("executiveMeetings.highlight.hint")}
           </p>
-          <div className="flex items-center gap-1.5">
+          <div className="flex items-center gap-1.5 flex-wrap">
             {HIGHLIGHT_COLOR_SWATCHES.map((c) => {
               const selected = highlightPrefs.color === c;
               return (
@@ -1297,6 +1297,16 @@ function ColumnsCustomizer({
                 />
               );
             })}
+            <button
+              type="button"
+              onClick={() =>
+                onHighlightPrefsChange({ ...DEFAULT_HIGHLIGHT_PREFS })
+              }
+              className="ml-1 text-[11px] text-[#0B1E3F] underline hover:no-underline disabled:opacity-50"
+              data-testid="em-highlight-reset"
+            >
+              {t("executiveMeetings.highlight.reset")}
+            </button>
           </div>
         </div>
       </PopoverContent>
@@ -1686,9 +1696,10 @@ function MeetingCard({
         <div className="min-w-0 flex-1 space-y-1">
           {showMeeting && (
             <>
-              <div className="font-semibold text-[#0B1E3F] leading-snug break-words">
-                {title}
-              </div>
+              <div
+                className="font-semibold text-[#0B1E3F] leading-snug break-words"
+                dangerouslySetInnerHTML={{ __html: safeHtml(title) }}
+              />
               {meeting.location && (
                 <div className="text-xs text-muted-foreground break-words">
                   {meeting.location}