feat(settings): LoTW 省份选择入口常驻 + 导入前预解析填充选项

- 省份入口从第一帧就在台站区：DXCC 未知时显示「导入证书后可选」占位，不可展开
- 选中 p12 后 400ms 防抖静默预解析（previewCertificate，只读不落库，密码副本用后清零），
  点「确认导入」之前下拉即可选省份；错密码/非 p12 静默保持占位，导入报错行为不变
- 修复导入成功不刷新 stationMeta：此前导入完成后省份下拉要关掉重开对话框才出现
- 无省份字段的国家（德国等）维持隐藏；后缀 seq 防慢预览覆盖新结果
- 新增 LoTWUploadRepositoryPreviewTest 2 例（TQSL 风格空密码夹具 test_tqsl_empty.p12，
  实测解析 DXCC 318、不落库、错密码映射 CERTIFICATE_PASSWORD）；en/zh 文案

core/presentation/src/main/res/values-zh/strings.xml

@@ -242,6 +242,8 @@
     <string name="prefs_lotw_upload_remove">移除证书</string>
     <string name="prefs_lotw_upload_station_title">台址</string>
     <string name="prefs_lotw_upload_region_hint">未选择</string>
+    <string name="prefs_lotw_upload_region_label">省份</string>
+    <string name="prefs_lotw_upload_region_pending">导入证书后可选</string>
     <string name="prefs_lotw_upload_grid">网格（逗号分隔，可多格）</string>
     <string name="prefs_lotw_upload_save">保存</string>
     <string name="prefs_lotw_upload_close">关闭</string>

core/presentation/src/main/res/values/strings.xml

@@ -271,6 +271,8 @@
     <string name="prefs_lotw_upload_remove">Remove certificate</string>
     <string name="prefs_lotw_upload_station_title">Station location</string>
     <string name="prefs_lotw_upload_region_hint">Not selected</string>
+    <string name="prefs_lotw_upload_region_label">Region</string>
+    <string name="prefs_lotw_upload_region_pending">Import certificate to select</string>
     <string name="prefs_lotw_upload_grid">Grid(s), comma-separated</string>
     <string name="prefs_lotw_upload_save">Save</string>
     <string name="prefs_lotw_upload_close">Close</string>