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/en.json

@@ -1747,7 +1747,11 @@
         "active": "Active",
         "cancel": "Cancel",
         "save": "Save",
-        "saving": "Saving..."
+        "saving": "Saving...",
+        "partner": "Partner",
+        "noPartner": "No partner",
+        "selectPartner": "Select partner",
+        "partnerAutoAssign": "Campaign will be automatically assigned to partner {{name}}"
       },
       "stats": {
         "title": "Campaign Statistics",

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",

src/locales/ru.json

@@ -2267,7 +2267,11 @@
         "active": "Активна",
         "cancel": "Отмена",
         "save": "Сохранить",
-        "saving": "Сохранение..."
+        "saving": "Сохранение...",
+        "partner": "Партнёр",
+        "noPartner": "Без партнёра",
+        "selectPartner": "Выберите партнёра",
+        "partnerAutoAssign": "Кампания будет автоматически привязана к партнёру {{name}}"
       },
       "stats": {
         "title": "Статистика кампании",

src/locales/zh.json

@@ -1485,7 +1485,11 @@
         "active": "启用",
         "cancel": "取消",
         "save": "保存",
-        "saving": "保存中..."
+        "saving": "保存中...",
+        "partner": "合作伙伴",
+        "noPartner": "无合作伙伴",
+        "selectPartner": "选择合作伙伴",
+        "partnerAutoAssign": "活动将自动分配给合作伙伴 {{name}}"
       },
       "stats": {
         "title": "活动统计",