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>

src/config/flags.ts

@@ -122,6 +122,14 @@ export const DEFAULT_FLAGS: FeatureFlag[] = [
     category: "module",
     overridable: true,
   },
+  {
+    key: "module.geoportal",
+    enabled: true,
+    label: "Geoportal",
+    description: "Harta interactiva cu parcele, cladiri si limite UAT",
+    category: "module",
+    overridable: true,
+  },
 
   // System flags
   {