feat: NASA Earthdata/GIBS Integration - Imagery-Switcher + FIRMS Layer

- imagery.js: WMTS-Support fuer NASA GIBS + 4 neue Quellen (MODIS Terra, VIIRS SNPP, GOES East/West)
- firms.js: Neuer VIIRS Thermal Anomalies Layer (375m, tagesaktuell, Braende/Industriewaerme)
- nightlights.js: NRT-Upgrade (dynamisches Datum statt hardcodiert 2024-01-01)
- index.html: Optgroups im Imagery-Select, FIRMS-Checkbox, Script-Tag
- app.js: FIRMS Toggle
- globe.css: dot-firms Farbe

Alle NASA-Daten kostenlos via GIBS WMTS, kein API-Key noetig.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

static/css/globe.css

@@ -790,6 +790,7 @@ html, body { height: 100%; overflow: hidden; background: var(--bg-primary); colo
 /* === GEOINT Tools === */
 .dot-nightlights { background: #ffd740; box-shadow: 0 0 4px rgba(255,215,64,0.4); }
 .dot-celltowers { background: #e040fb; }
+.dot-firms { background: #ff4400; box-shadow: 0 0 4px rgba(255,68,0,0.4); }
 
 .geoint-btn-row {
     display: flex;