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]>

src/app/constructCatalog.test.mjs

@@ -40,7 +40,7 @@ test('catalogs construct distinct layers and classification from their supplied
     signal: b.signal,
     surface: fixtureSurface(b.signal),
   });
-  assert.equal(first.layers.length, 32);
+  assert.equal(first.layers.length, 33);
   assert.ok(first.get('local-adsb'), 'Local ADS-B is registered');
   assert.deepEqual(
     first.metadata.find(({ id }) => id === 'local-adsb'),
@@ -61,6 +61,7 @@ test('catalogs construct distinct layers and classification from their supplied
     );
   assert.ok(first.get('fire-perimeters'));
   assert.ok(first.get('gnss-integrity'));
+  assert.ok(first.get('s2-ghostmaps'));
   assert.ok(first.get('transit'));
   const order = first.layers.map(({ id }) => id);
   assert.deepEqual(
@@ -154,7 +155,7 @@ test('Mapillary can be omitted or replaced without changing catalog membership',
     surface: fixtureSurface(lifetime.signal),
   };
   const catalog = createApplicationCatalog(options);
-  assert.equal(catalog.layers.length, 32);
+  assert.equal(catalog.layers.length, 33);
   assert.deepEqual(catalog.get('street-level').providerIds, []);
   assert.equal(
     catalogControlServices(catalog).streetLevelLayer,