feat: add S2 GhostMaps live intel layer

Adds an "S2 GhostMaps" layer (Events group) that renders S2 Underground's
GhostMaps KMZ exports (Common Intelligence Picture, Kinetic 30d, Border
Crisis, Iran CIP/Kinetic, Yemen FLOT, latest incident drop).

- server/providers/ghostMaps.js: watcher polls the repo's git smart-HTTP
  ref advertisement (default every 15s, GHOSTMAPS_POLL_SECONDS), fetches
  the tree only on a new head, caches commit-pinned files by blob sha and
  pushes catalog updates to browsers over SSE (/api/ghostmaps/events).
- src/layers/ghostMaps: KML reader, ArcGIS popup-table parsing, per-product
  data sources, product chips, horizon-culled pins, report cards.
- Unit tests, QA gate (scripts/qa-ghostmaps.mjs), credits (CC BY-NC-SA 4.0),
  i18n, voice manifest, layer-state token 5.

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

package.json

@@ -168,6 +168,7 @@
     "./layers/recent-imagery/source": "./src/layers/recentImagery/source.js",
     "./layers/perimeters": "./src/layers/perimeters/index.js",
     "./layers/gnss": "./src/layers/gnss/index.js",
+    "./layers/ghostmaps": "./src/layers/ghostMaps/index.js",
     "./sources/firms-csv": "./src/data/firmsCsv.js",
     "./layers/firms": "./src/layers/firms/index.js",
     "./layers/satellites": "./src/layers/satellites/index.js",
@@ -244,6 +245,7 @@
     "./layers/earthquakes/source": "./src/layers/earthquakes/source.js",
     "./layers/perimeters/source": "./src/layers/perimeters/source.js",
     "./layers/gnss/source": "./src/layers/gnss/source.js",
+    "./layers/ghostmaps/source": "./src/layers/ghostMaps/source.js",
     "./layers/firms/source": "./src/layers/firms/source.js",
     "./layers/installations/source": "./src/layers/installations/source.js",
     "./layers/launches/source": "./src/layers/launches/source.js",