v0.5.0: FIRMS fire hotspots, space weather, internet outages

New intelligence layers:
- NASA FIRMS VIIRS fire hotspots (5K+ global thermal anomalies, flame icons)
- NOAA space weather badge (Kp index in status bar)
- IODA regional internet outage monitoring (grey markers, BGP/ping only)

Key improvements:
- Fire clusters use flame-shaped icons (not circles) for clear differentiation
- Internet outages are region-level with reliable datasources only
- Removed radiation layer (no viable free real-time API)
- All outage markers grey to avoid color confusion with other layers
- Filtered out merit-nt telescope data that produced misleading percentages

Updated changelog modal, README, and package.json for v0.5.0.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "frontend",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "private": true,
   "scripts": {
     "dev": "concurrently \"npm run dev:frontend\" \"npm run dev:backend\"",