deps: react-leaflet 1.8 -> 4.2 (+ leaflet 1.9) — the last legacy react-* lib

Ground-up hooks rewrite of the app's core map. Removes the final batch of
React-19-blocking warnings (legacy context on Map/LayersControl/TileLayer/
Marker/CircleMarker/Circle/Tooltip + ReactDOM.render from the old controls).

Core: <Map> -> <MapContainer>; .leafletElement refs (6 files) -> the map/
layer instances directly, via a <MapReady> child (useMap) + plain refs on
Marker/Circle/GeoJSON; controlled viewport (onViewportChanged + state.center/
zoom) -> <MapEvents> (useMapEvents moveend/zoomend) + imperative setView;
onClick -> eventHandlers={{click}}; Path styling -> pathOptions/style;
subsUnion takes the L.Map directly.

The 4 v1-only plugins reimplemented (new in-repo helpers under Maps/):
- react-leaflet-control -> MapControl (L.Control + createPortal)
- react-leaflet-google  -> GoogleMutantLayer (createLayerComponent +
  leaflet.gridlayer.googlemutant; Google Maps API already loaded by Gkeys)
- react-leaflet-fullscreen -> createControlComponent + leaflet.fullscreen
- leaflet-sleep / leaflet-graphicscale kept as vanilla (work on leaflet 1.9)

Browser-verified: /fires (tiles, OSM+Google layer switch, custom control,
fullscreen, graphic scale, pan/zoom -> re-fetch, no NaN), fire detail
(GeoJSON rect + fitBounds), home (3 maps coexist; SelectionMap draggable
marker -> updatePosition + distance circle). Console now shows 0 React
warnings on home/fires. REST smoke byte-identical.

imports/ui/pages/Subscriptions/SubscriptionsMap.js

@@ -8,14 +8,15 @@ import { Button, ButtonGroup, Row, Col } from 'react-bootstrap';
 import { Meteor } from 'meteor/meteor';
 import { withTracker } from 'meteor/react-meteor-data';
 import { Trans, withTranslation } from 'react-i18next';
-import { Map } from 'react-leaflet';
+import { MapContainer } from 'react-leaflet';
 import { Helmet } from 'react-helmet-async';
 import L from 'leaflet';
 import 'leaflet/dist/leaflet.css';
 import 'leaflet-graphicscale/dist/Leaflet.GraphicScale.min.css';
 import 'leaflet-graphicscale/dist/Leaflet.GraphicScale.min.js';
 import 'leaflet-sleep/Leaflet.Sleep.js';
-import Control from 'react-leaflet-control';
+import MapControl from '/imports/ui/components/Maps/MapControl';
+import { MapReady } from '/imports/ui/components/Maps/MapBridge';
 import CenterInMyPosition from '/imports/ui/components/CenterInMyPosition/CenterInMyPosition';
 import subsUnion from '/imports/ui/components/Maps/SubsUnion/SubsUnion';
 import DefMapLayers from '/imports/ui/components/Maps/DefMapLayers';
@@ -39,16 +40,18 @@ class SubscriptionsMap extends React.Component {
       },
       init: true
     };
-  }
-
-  componentDidMount() {
-    if (this.subscriptionsMap) {
-      this.addScale();
-    }
+    this.handleMapReady = this.handleMapReady.bind(this);
   }
 
   getMap() {
-    return this.subscriptionsMap.leafletElement;
+    return this.map;
+  }
+
+  // v4: <MapReady> hands us the ready Leaflet map (no ref/.leafletElement)
+  handleMapReady(map) {
+    this.map = map;
+    this.addScale();
+    this.handleLeafletLoad(map);
   }
 
   addScale() {
@@ -77,8 +80,9 @@ class SubscriptionsMap extends React.Component {
   }
 
   centerOnUserLocation(viewport) {
-    console.log(`viewport: ${JSON.stringify(viewport)}`);
     this.setState({ init: false, viewport });
+    // v4 map is uncontrolled: move it imperatively
+    if (this.map) this.map.setView(viewport.center, viewport.zoom);
   }
 
   gotoParticipe() {
@@ -112,15 +116,10 @@ class SubscriptionsMap extends React.Component {
              <Trans>En verde, las zonas vigiladas por nuestros usuari@s actualmente</Trans>&nbsp;(*)
            </Row>
          </Col>
-         <Map
-             ref={(map) => {
-                 this.subscriptionsMap = map;
-                 this.handleLeafletLoad(map);
-               }}
+         <MapContainer
              zoom={this.state.viewport.zoom}
              center={this.state.viewport.center}
              className="subscriptionsmap-leaflet-container"
-             animate
              sleep={window.location.pathname === '/' && !isChrome}
              sleepTime={10750}
              wakeTime={750}
@@ -130,8 +129,9 @@ class SubscriptionsMap extends React.Component {
              wakeMessageTouch={this.props.t('Pulsa para activar')}
              sleepOpacity={0.6}
          >
+           <MapReady onReady={this.handleMapReady} />
            <DefMapLayers gray />
-           <Control position="topright" >
+           <MapControl position="topright" >
              <ButtonGroup>
                <CenterInMyPosition onClick={viewport => this.centerOnUserLocation(viewport)} onlyIcon {... this.props} />
                <Button
@@ -141,9 +141,9 @@ class SubscriptionsMap extends React.Component {
                  {this.props.t('Participa')}
                </Button>
              </ButtonGroup>
-           </Control>
+           </MapControl>
            <FullScreenMap />
-         </Map>
+         </MapContainer>
          <Row>
            <Col xs={12} sm={12} md={12} lg={12}>
              <p className="subscriptionsmap-footnote"><span style={{ paddingRight: '5px' }}>(*)</span><Trans i18nKey="mapPrivacy" parent="span"><em>Para preservar la privacidad de nuestros usuarios/as, los datos reflejados están aleatoriamente alterados y son solo orientativos.</em></Trans></p>