i18n(pt): apply review round 2

Three-model review (astra, sol, fable), round 2: 29 of 30 findings
applied, one of them in part.

- pt: FIRMS «mais recente há», CCTV «cruzamentos», degraded radio
  directory, «{layers}: ativação recente» for any layer list, «Sem
  imagem», NIVELADO, AJUSTA-SE, quoted Provider Settings, V/S kept on
  the ADS-B card, no-break space in «(24 h)» / «(30 d)», and more
  (see docs/translations/pt.md).
- Malformed cyclone snapshot is now a catalog message (all locales).
- Markup supports data-i18n-context; the radio STATION TAG option uses
  "radio tag|All", so it no longer flips gender when the list loads.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/i18n/locales/zh-CN.json

@@ -1203,6 +1203,7 @@
   "Malformed weather manifest": "天气清单格式错误",
   "Weather request timed out": "天气请求超时",
   "Cyclone request timed out": "气旋请求超时",
+  "Malformed cyclone snapshot": "气旋快照格式错误",
   "Temperature field unavailable": "温度场不可用",
   "Mean sea level pressure field unavailable": "平均海平面气压场不可用",
   "Wind upstream unavailable": "风场上游数据源不可用",