chore(phase0): PortOne 잔재 제거 — 계좌이체 단일 소스 확정, saju 결제 CTA 제거

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package-lock.json

@@ -11,7 +11,6 @@
         "@anthropic-ai/sdk": "^0.79.0",
         "@google-analytics/data": "^5.2.1",
         "@google/generative-ai": "^0.24.1",
-        "@portone/browser-sdk": "^0.1.3",
         "@supabase/ssr": "^0.5.2",
         "@supabase/supabase-js": "^2.99.0",
         "clsx": "^2.1.1",
@@ -1381,11 +1380,6 @@
         "node": ">=14"
       }
     },
-    "node_modules/@portone/browser-sdk": {
-      "version": "0.1.3",
-      "resolved": "https://registry.npmjs.org/@portone/browser-sdk/-/browser-sdk-0.1.3.tgz",
-      "integrity": "sha512-GRmXb8gBLs/23CES1YRvzMggbL8+tFeH5WS9YSA6WUPu5/9kgRKKZLeC25N2raq3zVJd9OfDTeSf0tUr27vF1Q=="
-    },
     "node_modules/@protobufjs/aspromise": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/@protobufjs/aspromise/-/aspromise-1.1.2.tgz",