feat: admin partner settings page, partner section visibility toggle, custom requisites text

- New AdminPartnerSettings page with validation (pattern from AdminTicketSettings)
- Settings gear button on AdminPartners header
- Hide partner/withdrawal sections when partner_section_visible is false
- Use custom requisites_text as label in withdrawal form
- i18n keys for ru/en

src/App.tsx

@@ -60,6 +60,7 @@ const AdminCampaignCreate = lazy(() => import('./pages/AdminCampaignCreate'));
 const AdminCampaignStats = lazy(() => import('./pages/AdminCampaignStats'));
 const AdminCampaignEdit = lazy(() => import('./pages/AdminCampaignEdit'));
 const AdminPartners = lazy(() => import('./pages/AdminPartners'));
+const AdminPartnerSettings = lazy(() => import('./pages/AdminPartnerSettings'));
 const AdminPartnerDetail = lazy(() => import('./pages/AdminPartnerDetail'));
 const AdminApplicationReview = lazy(() => import('./pages/AdminApplicationReview'));
 const AdminPartnerCommission = lazy(() => import('./pages/AdminPartnerCommission'));
@@ -591,6 +592,16 @@ function App() {
             </AdminRoute>
           }
         />
+        <Route
+          path="/admin/partners/settings"
+          element={
+            <AdminRoute>
+              <LazyPage>
+                <AdminPartnerSettings />
+              </LazyPage>
+            </AdminRoute>
+          }
+        />
         <Route
           path="/admin/partners/applications/:id/review"
           element={