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/en.json

@@ -1107,7 +1107,29 @@
       "title": "Subscription plans",
       "monthlyPrice": "Monthly price (Toman)",
       "maxOrders": "Max orders per day",
-      "saved": "Plan saved"
+      "saved": "Plan saved",
+      "active": "Active",
+      "nameFa": "Name (Persian)",
+      "nameEn": "Name (English)",
+      "sortOrder": "Sort order",
+      "billable": "Billable online",
+      "limitsTitle": "Limits",
+      "featuresTitle": "Features",
+      "allFeatures": "All features",
+      "allFeaturesNote": "This plan includes all features (current and future).",
+      "save": "Save",
+      "limits": {
+        "maxOrders": "Orders/day",
+        "maxTables": "Tables",
+        "maxTerminals": "POS terminals",
+        "maxBranches": "Branches",
+        "maxCategories": "Menu categories",
+        "maxItems": "Menu items",
+        "maxCustomers": "Customers",
+        "maxReportDays": "Report history (days)",
+        "maxSms": "SMS/month",
+        "maxAi3d": "AI 3D/month"
+      }
     },
     "settings": {
       "title": "Application settings",