Task #348: Arabic-friendly Executive Meetings audit log

- Reorder audit table columns to RTL order: المستخدم، الوقت، الإجراء،
  النوع، التغييرات. Drop the entityId ("المعرف") column entirely. Update
  loading/empty colSpan from 6 to 5 to match the new column count.
- Rename audit.col.actor copy: "المنفّذ" → "المستخدم" (ar.json) and
  "Actor" → "User" (en.json). Underlying data field name unchanged.
- Localize the Changes cell in AuditDiffSummary:
  - Field-name labels (titleAr, titleEn, meetingDate, dailyNumber,
    startTime, endTime, location, meetingUrl, platform, status,
    isHighlighted, notes, assignedTo, taskType, dueAt, reviewDecision,
    reviewNotes) now resolve via executiveMeetings.audit.field.* with a
    raw-key fallback so unknown future fields don't crash the row.
  - Enum values render via existing label namespaces:
    `platform` → executiveMeetings.platform.*, `status` →
    executiveMeetings.status.*, `isHighlighted` → executiveMeetings.common.yes/no.
  - Both the diff view and the single-side created/removed view use the
    same labelForKey/fmtValue helpers.
- Added matching audit.field.* keys to ar.json and en.json with sensible
  Arabic and English labels.
- No test changes needed: no existing test asserts on the old column
  count, the "Actor"/"المنفّذ" header, the entityId column, or raw
  English field names in Changes.
- tsc passes for @workspace/tx-os.

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

@@ -1343,7 +1343,7 @@
       "all": "الكل",
       "col": {
         "when": "الوقت",
-        "actor": "المنفّذ",
+        "actor": "المستخدم",
         "action": "الإجراء",
         "entity": "النوع",
         "entityId": "المعرف",
@@ -1353,6 +1353,25 @@
       "created": "تم إنشاء",
       "removed": "تم حذف",
       "moreChanges": "تغييرات أخرى",
+      "field": {
+        "titleAr": "العنوان",
+        "titleEn": "العنوان (إنجليزي)",
+        "meetingDate": "التاريخ",
+        "dailyNumber": "الرقم اليومي",
+        "startTime": "وقت البدء",
+        "endTime": "وقت الانتهاء",
+        "location": "المكان",
+        "meetingUrl": "رابط الاجتماع",
+        "platform": "المنصة",
+        "status": "الحالة",
+        "isHighlighted": "مميّز",
+        "notes": "ملاحظات",
+        "assignedTo": "المُسند إليه",
+        "taskType": "نوع المهمة",
+        "dueAt": "موعد الاستحقاق",
+        "reviewDecision": "قرار المراجعة",
+        "reviewNotes": "ملاحظات المراجعة"
+      },
       "entity": {
         "meeting": "اجتماع",
         "attendee": "حاضر",