style(ftmap): one world, themed ground — here and on every map

The FT map wrapped the planet into a row of copies and showed Leaflet's
hard-coded grey beyond it. noWrap tiles inside hard bounds now, like the
grid-square map already did — and the container background override moves to
style.css so EVERY map's surround follows the theme's card surface instead
of #ddd (the grid map's per-div fix was losing to leaflet.css specificity).

frontend/src/components/FTMapPanel.tsx

@@ -51,10 +51,14 @@ export function FTMapPanel({ decodes, myGrid }: { decodes: FTMapDecode[]; myGrid
   // The map itself, once.
   useEffect(() => {
     if (!divRef.current || mapRef.current) return;
+    // ONE world: noWrap tiles inside hard bounds, no side-by-side copies —
+    // and the space beyond the edge is the theme's own surface (style.css).
     const m = L.map(divRef.current, {
       zoomControl: true, attributionControl: true,
-      worldCopyJump: true, preferCanvas: true,
+      worldCopyJump: false, preferCanvas: true,
       center: [25, 0], zoom: 2, minZoom: 2,
+      maxBounds: L.latLngBounds(L.latLng(-85.0511, -180), L.latLng(85.0511, 180)),
+      maxBoundsViscosity: 1,
     });
     mapRef.current = m;
     layerRef.current = L.layerGroup().addTo(m);
@@ -67,7 +71,11 @@ export function FTMapPanel({ decodes, myGrid }: { decodes: FTMapDecode[]; myGrid
     if (!m) return;
     baseRef.current?.remove(); labelsRef.current?.remove();
     const bm = BASEMAPS[basemap];
-    const opts: L.TileLayerOptions = { maxNativeZoom: bm.maxNativeZoom, noWrap: false };
+    const opts: L.TileLayerOptions = {
+      maxNativeZoom: bm.maxNativeZoom,
+      noWrap: true,
+      bounds: L.latLngBounds(L.latLng(-85.0511, -180), L.latLng(85.0511, 180)),
+    };
     baseRef.current = L.tileLayer(bm.url, { ...opts, attribution: bm.attr, subdomains: bm.subdomains ?? 'abc' }).addTo(m);
     if (bm.labelsUrl) labelsRef.current = L.tileLayer(bm.labelsUrl, opts).addTo(m);
     localStorage.setItem('opslog.ftmapBase', basemap);

frontend/src/style.css

@@ -1086,3 +1086,10 @@
 .overflow-scroll {
   overscroll-behavior: contain;
 }
+
+/* The ground beside the planet, on every map: Leaflet paints its container a
+   hard-coded light grey (#ddd), which reads as a broken tile against any
+   theme. The surround follows the theme's own card surface instead. */
+.leaflet-container {
+  background: var(--card) !important;
+}