feat: add Geoportal module with MapLibre GL JS + Martin vector tiles

Phase 1 of the geoportal implementation:

Infrastructure:
- Martin vector tile server in docker-compose (port 3010)
- PostGIS setup SQL for GisUat: native geom column, Esri→PostGIS
  trigger, GiST index, gis_uats view for Martin auto-discovery

Geoportal module (src/modules/geoportal/):
- map-viewer.tsx: MapLibre GL JS canvas with OSM base, Martin MVT
  sources (gis_uats, gis_terenuri, gis_cladiri), click-to-inspect,
  zoom-level-aware layer visibility, layer styling
- layer-panel.tsx: collapsible sidebar with layer toggles
- geoportal-module.tsx: standalone page wrapper
- Module registered in config/modules.ts, flags.ts, i18n

ParcelSync integration:
- 6th tab "Harta" with lazy-loaded MapViewer (ssr: false)
- Centered on selected UAT

Dependencies: maplibre-gl v5.21.0

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

package.json

@@ -20,6 +20,7 @@
     "jspdf": "^4.2.0",
     "jszip": "^3.10.1",
     "lucide-react": "^0.564.0",
+    "maplibre-gl": "^5.21.0",
     "minio": "^8.0.6",
     "next": "16.1.6",
     "next-auth": "^4.24.13",