feat(geodata): add standard source presets (#6504)

* feat(geodata): add standard source presets

Expose the existing geofile allowlist to the Geodata editor so administrators can configure the supported scheduled downloads without copying URLs manually

Tested with npm run test, npm run lint, npm run typecheck, npm run format:check, and go test ./internal/web/service ./internal/web/controller -run '^(TestStandardGeodataSources|TestGeodata)' -count=1

Assisted-by: OpenCode:openai/gpt-5.6-terra (mostly)

* fix(geodata): preserve custom source entries

Add missing standard sources instead of replacing existing custom entries.

Assisted-by: OpenCode:openai/gpt-5.6-terra (mostly)

internal/web/translation/ja-JP.json

@@ -221,6 +221,7 @@
       "geodataOutbound": "アウトバウンド経由でダウンロード（任意）",
       "geodataFile": "ファイル名",
       "geodataAddFile": "ファイルを追加",
+      "geodataUseStandardSources": "標準ソースを使用",
       "geodataSaveRestart": "保存して Xray を再起動",
       "geodataConfirmTitle": "geodata 設定を保存しますか？",
       "geodataConfirmContent": "Xray 設定テンプレートを更新し、Xray を再起動します。",