feat(geoportal-v2): "S2" basemap — Sentinel-2 cloudless annual mosaics

Adds a 6th basemap option ("S2") backed by EOX's free, public,
CORS-open Sentinel-2 cloudless WMTS service. Annual mosaics from 2016
to 2024 (2025/2026 not yet shipped by EOX); 10 m/pixel resolution
good for large-scale rural change detection (deforestation,
greenhouses, halls, agriculture) but not for individual buildings.

Companion to the Wayback basemap shipped earlier — Wayback gives
high-res city detail at irregular snapshot dates, Sentinel-2 gives
predictable yearly cadence at coarse rural-scale resolution.

UI mirrors Wayback: when "S2" is selected the switcher reveals a year
dropdown beneath the basemap row; the map-viewer rebuilds the raster
source with the right EOX layer ID. Default year = latest (2024).

Note on licensing: EOX's 2018+ mosaics are CC BY-NC-SA 4.0 — non-
commercial. The UI surfaces this + the commercial-licence pointer
(cloudless.eox.at). 2016 (s2cloudless) + 2017 are CC BY 4.0, no
non-commercial restriction.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/modules/geoportal/v2/basemap-switcher.tsx

@@ -8,8 +8,15 @@ import {
   latestWaybackRelease,
   type WaybackRelease,
 } from "./wayback-catalog";
+import { SENTINEL_YEARS, type SentinelYear } from "./sentinel-catalog";
 
-export type BasemapId = "liberty" | "dark" | "satellite" | "google" | "wayback";
+export type BasemapId =
+  | "liberty"
+  | "dark"
+  | "satellite"
+  | "google"
+  | "wayback"
+  | "sentinel";
 
 const OPTIONS: Array<{ id: BasemapId; label: string }> = [
   { id: "liberty", label: "Liberty" },
@@ -17,6 +24,7 @@ const OPTIONS: Array<{ id: BasemapId; label: string }> = [
   { id: "satellite", label: "Satelit" },
   { id: "google", label: "Google" },
   { id: "wayback", label: "Istoric" },
+  { id: "sentinel", label: "S2" },
 ];
 
 interface Props {
@@ -26,6 +34,10 @@ interface Props {
   waybackReleaseId?: string | null;
   /** Fired when the user picks a different Wayback date. */
   onWaybackReleaseChange?: (release: WaybackRelease) => void;
+  /** Selected Sentinel-2 cloudless year (only meaningful when value=sentinel). */
+  sentinelYear?: string | null;
+  /** Fired when the user picks a different Sentinel-2 year. */
+  onSentinelYearChange?: (year: SentinelYear) => void;
 }
 
 export function BasemapSwitcher({
@@ -33,6 +45,8 @@ export function BasemapSwitcher({
   onChange,
   waybackReleaseId,
   onWaybackReleaseChange,
+  sentinelYear,
+  onSentinelYearChange,
 }: Props) {
   const [releases, setReleases] = useState<WaybackRelease[] | null>(null);
   const [loading, setLoading] = useState(false);
@@ -80,6 +94,36 @@ export function BasemapSwitcher({
         </div>
       </div>
 
+      {value === "sentinel" && (
+        <div className="rounded-md border bg-background/95 px-2 py-1.5 shadow-sm backdrop-blur">
+          <label className="flex items-center gap-1.5 text-[10px] font-medium uppercase tracking-wide text-muted-foreground">
+            <Clock className="h-3 w-3" />
+            An mosaic Sentinel-2
+          </label>
+          <select
+            value={sentinelYear ?? SENTINEL_YEARS[0]!.year}
+            onChange={(e) => {
+              const y = SENTINEL_YEARS.find((s) => s.year === e.target.value);
+              if (y && onSentinelYearChange) onSentinelYearChange(y);
+            }}
+            className="mt-1 w-full rounded border bg-background px-1.5 py-1 text-xs"
+          >
+            {SENTINEL_YEARS.map((y) => (
+              <option key={y.year} value={y.year}>
+                {y.year}
+                {y.year === "2016" ? " (+2017)" : ""}
+              </option>
+            ))}
+          </select>
+          <p className="mt-1 text-[9px] leading-tight text-muted-foreground">
+            Mozaic anual cloud-free Sentinel-2 (rezoluție ~10 m). Bun
+            pentru schimbări rurale large-scale (defrișări, hale,
+            sere). Nu vezi case sau detalii fine. © EOX / Copernicus.
+            Uz comercial: cloudless.eox.at.
+          </p>
+        </div>
+      )}
+
       {value === "wayback" && (
         <div className="rounded-md border bg-background/95 px-2 py-1.5 shadow-sm backdrop-blur">
           <label className="flex items-center gap-1.5 text-[10px] font-medium uppercase tracking-wide text-muted-foreground">

src/modules/geoportal/v2/geoportal-v2.tsx

@@ -5,6 +5,7 @@ import dynamic from "next/dynamic";
 import { useSession } from "next-auth/react";
 import { BasemapSwitcher, type BasemapId } from "./basemap-switcher";
 import type { WaybackRelease } from "./wayback-catalog";
+import type { SentinelYear } from "./sentinel-catalog";
 import { SearchBar, type FeatureHit, type UatHit } from "./search-bar";
 import {
   FeatureInfoPanel,
@@ -30,6 +31,7 @@ export function GeoportalV2() {
   const basicPanel = Boolean((session as { basicPanel?: boolean } | null)?.basicPanel);
   const [basemap, setBasemap] = useState<BasemapId>("liberty");
   const [waybackRelease, setWaybackRelease] = useState<WaybackRelease | null>(null);
+  const [sentinelYear, setSentinelYear] = useState<SentinelYear | null>(null);
   const [clicked, setClicked] = useState<ClickedFeatureLite | null>(null);
 
   const handleFeatureClick = useCallback((f: ClickedFeatureLite | null) => {
@@ -62,6 +64,7 @@ export function GeoportalV2() {
         ref={mapRef}
         basemap={basemap}
         waybackReleaseId={waybackRelease?.id ?? null}
+        sentinelYear={sentinelYear?.year ?? null}
         onFeatureClick={handleFeatureClick}
         selectedFeature={clicked}
         className="h-full w-full"
@@ -82,6 +85,8 @@ export function GeoportalV2() {
           onChange={setBasemap}
           waybackReleaseId={waybackRelease?.id ?? null}
           onWaybackReleaseChange={setWaybackRelease}
+          sentinelYear={sentinelYear?.year ?? null}
+          onSentinelYearChange={setSentinelYear}
         />
         {clicked && (
           <FeatureInfoPanel

src/modules/geoportal/v2/map-viewer.tsx

@@ -8,6 +8,7 @@ import { Protocol as PmtilesProtocol } from "pmtiles";
 import { cn } from "@/shared/lib/utils";
 import type { BasemapId } from "./basemap-switcher";
 import { waybackTileUrl } from "./wayback-catalog";
+import { sentinelTileUrl, SENTINEL_YEARS } from "./sentinel-catalog";
 import type { ClickedFeatureLite } from "./feature-info-panel";
 
 // Ensure MapLibre CSS loaded (static import fails in standalone build)
@@ -79,6 +80,16 @@ const BASEMAPS: Record<BasemapId, BasemapDef> = {
     tileSize: 256,
     maxzoom: 19,
   },
+  // Sentinel-2 cloudless yearly mosaic from EOX. Default fallback is the
+  // latest year; actual year picked by the sentinelYear prop and applied
+  // through buildStyle below.
+  sentinel: {
+    type: "raster",
+    tiles: [sentinelTileUrl(SENTINEL_YEARS[0]!.layerId)],
+    attribution: '&copy; <a href="https://s2maps.eu">Sentinel-2 cloudless</a> / EOX',
+    tileSize: 256,
+    maxzoom: 17,
+  },
 };
 
 const PM_SRC = "gis-pmtiles";
@@ -117,6 +128,9 @@ interface Props {
   /** Wayback release id; only honored when basemap=="wayback". null = use
    *  the basemap-default fallback (latest release baked in BASEMAPS). */
   waybackReleaseId?: string | null;
+  /** Sentinel-2 cloudless year string ("2024", "2023", …); only honored
+   *  when basemap=="sentinel". null = latest year (basemap default). */
+  sentinelYear?: string | null;
   onFeatureClick: (f: ClickedFeatureLite | null) => void;
   /** Currently selected feature — drives the highlight overlay so the
    * user sees which parcel/building corresponds to the open info panel. */
@@ -125,7 +139,14 @@ interface Props {
 }
 
 export const MapViewer = forwardRef<MapViewerHandle, Props>(function MapViewer(
-  { basemap, waybackReleaseId, onFeatureClick, selectedFeature, className },
+  {
+    basemap,
+    waybackReleaseId,
+    sentinelYear,
+    onFeatureClick,
+    selectedFeature,
+    className,
+  },
   ref,
 ) {
   const containerRef = useRef<HTMLDivElement>(null);
@@ -403,6 +424,9 @@ export const MapViewer = forwardRef<MapViewerHandle, Props>(function MapViewer(
     let def = BASEMAPS[basemap];
     if (basemap === "wayback" && waybackReleaseId && def.type === "raster") {
       def = { ...def, tiles: [waybackTileUrl(waybackReleaseId)] };
+    } else if (basemap === "sentinel" && sentinelYear && def.type === "raster") {
+      const y = SENTINEL_YEARS.find((s) => s.year === sentinelYear);
+      if (y) def = { ...def, tiles: [sentinelTileUrl(y.layerId)] };
     }
     setReady(false);
 
@@ -487,7 +511,7 @@ export const MapViewer = forwardRef<MapViewerHandle, Props>(function MapViewer(
       map.remove();
       mapRef.current = null;
     };
-  }, [basemap, waybackReleaseId, addGisLayers, onFeatureClick]);
+  }, [basemap, waybackReleaseId, sentinelYear, addGisLayers, onFeatureClick]);
 
   useImperativeHandle(
     ref,

src/modules/geoportal/v2/sentinel-catalog.ts

@@ -0,0 +1,50 @@
+// EOX Sentinel-2 cloudless — public, CORS-open annual mosaics of
+// cloud-free Sentinel-2 imagery. Free for non-commercial use; commercial
+// licence at cloudless.eox.at. Rezolutie 10 m/pixel — bun pentru
+// schimbari rurale large-scale (defrisari, sere, hale, terenuri agri-
+// cole), nu pentru detaliu de cladire/strada.
+//
+// Layer IDs follow EOX's convention `s2cloudless-YYYY_3857` for Web
+// Mercator (which MapLibre uses). 2016 is served under the legacy
+// `s2cloudless_3857` ID (pooled with 2017). Available years update
+// when EOX ships the new mosaic — refresh the constants here when
+// 2025/2026 ship.
+//
+// Tile URL template:
+//   https://tiles.maps.eox.at/wmts/1.0.0/<layerId>/default/g/{z}/{y}/{x}.jpg
+
+export type SentinelYear = {
+  /** ISO year string for the picker label. Special: "2016" maps to the
+   *  legacy pooled `s2cloudless` layer. */
+  year: string;
+  /** WMTS layer identifier on tiles.maps.eox.at. */
+  layerId: string;
+};
+
+// Hardcoded for now — EOX adds one mosaic per year, no live catalog to
+// poll (their /WMTSCapabilities.xml works but is ~150 KB and the year
+// list grows by exactly one entry per year). Update this array when
+// EOX ships a new mosaic; until then we save the round-trip on every
+// map load.
+export const SENTINEL_YEARS: SentinelYear[] = [
+  { year: "2024", layerId: "s2cloudless-2024_3857" },
+  { year: "2023", layerId: "s2cloudless-2023_3857" },
+  { year: "2022", layerId: "s2cloudless-2022_3857" },
+  { year: "2021", layerId: "s2cloudless-2021_3857" },
+  { year: "2020", layerId: "s2cloudless-2020_3857" },
+  { year: "2019", layerId: "s2cloudless-2019_3857" },
+  { year: "2018", layerId: "s2cloudless-2018_3857" },
+  { year: "2017", layerId: "s2cloudless-2017_3857" },
+  // EOX pools 2016 + 2017 under the legacy bare identifier.
+  { year: "2016", layerId: "s2cloudless_3857" },
+];
+
+/** Build the MapLibre raster tile URL template for a given EOX layer. */
+export function sentinelTileUrl(layerId: string): string {
+  return `https://tiles.maps.eox.at/wmts/1.0.0/${layerId}/default/g/{z}/{y}/{x}.jpg`;
+}
+
+/** Default to the latest available year. */
+export function latestSentinelYear(): SentinelYear {
+  return SENTINEL_YEARS[0]!;
+}