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/zh-CN.json

@@ -221,6 +221,7 @@
       "geodataOutbound": "通过出站下载（可选）",
       "geodataFile": "文件名",
       "geodataAddFile": "添加文件",
+      "geodataUseStandardSources": "使用标准来源",
       "geodataSaveRestart": "保存并重启 Xray",
       "geodataConfirmTitle": "保存 geodata 设置？",
       "geodataConfirmContent": "将更新 Xray 配置模板并重启 Xray。",