feat(plans): Stage 4 — full admin plan/feature editor

The admin → Plans screen now edits EVERYTHING per plan (the backend already
accepted it; only the UI was partial):
- All limits (orders/day, tables, terminals, branches, menu categories, menu
  items, customers, report history, SMS, AI-3D) with an "unlimited (∞)" toggle.
- Display names (fa/en), monthly price, sort order, billable-online, active on/off.
- Per-plan feature checkboxes grouped by module, plus an "all features (*)" toggle
  (Enterprise). Sourced from the live feature catalog (/api/admin/features).
- Plans listed in sort order (Free·Starter·Pro·Business·Enterprise).
- i18n fa/en/ar.

Admin tsc + build clean.

web/admin/messages/ar.json

@@ -1114,7 +1114,29 @@
       "title": "خطط الاشتراك",
       "monthlyPrice": "السعر الشهري (تومان)",
       "maxOrders": "حد الطلبات اليومي",
-      "saved": "تم الحفظ"
+      "saved": "تم الحفظ",
+      "active": "مفعل",
+      "nameFa": "الاسم (فارسي)",
+      "nameEn": "الاسم (إنجليزي)",
+      "sortOrder": "الترتيب",
+      "billable": "قابل للدفع عبر الإنترنت",
+      "limitsTitle": "الحدود",
+      "featuresTitle": "الميزات",
+      "allFeatures": "كل الميزات",
+      "allFeaturesNote": "تشمل هذه الباقة جميع الميزات الحالية والمستقبلية.",
+      "save": "حفظ",
+      "limits": {
+        "maxOrders": "طلبات/يوم",
+        "maxTables": "الطاولات",
+        "maxTerminals": "أجهزة POS",
+        "maxBranches": "الفروع",
+        "maxCategories": "فئات القائمة",
+        "maxItems": "أصناف القائمة",
+        "maxCustomers": "العملاء",
+        "maxReportDays": "سجل التقارير (أيام)",
+        "maxSms": "رسائل/شهر",
+        "maxAi3d": "3D/شهر"
+      }
     },
     "settings": {
       "title": "إعدادات التطبيق",