feat: partner-campaign integration in admin UI

- Add partner badge to campaigns list
- Add partner selector dropdown in campaign edit
- Support ?partnerId= query param in campaign create (replaces separate page)
- Filter already-assigned campaigns in partner assign flow
- Show taken campaigns greyed out with partner name
- Delete AdminPartnerCampaignCreate (replaced by query param approach)
- Add partner translations (ru, en, zh, fa)

src/locales/fa.json

@@ -1486,7 +1486,11 @@
         "active": "فعال",
         "cancel": "لغو",
         "save": "ذخیره",
-        "saving": "در حال ذخیره..."
+        "saving": "در حال ذخیره...",
+        "partner": "شریک",
+        "noPartner": "بدون شریک",
+        "selectPartner": "انتخاب شریک",
+        "partnerAutoAssign": "کمپین به طور خودکار به شریک {{name}} اختصاص داده می‌شود"
       },
       "stats": {
         "title": "آمار کمپین",