fix(maps): zooming stays centred on the grid and decode maps

The hard maxBounds added for the single-world look fought the zoom: with
the world smaller than the window the clamp dragged every zoom step into
a corner. The noWrap tiles already guarantee one world on their own, so
the bounds go — on both maps.

frontend/src/components/FTMapPanel.tsx

@@ -55,10 +55,10 @@ export function FTMapPanel({ decodes, myGrid }: { decodes: FTMapDecode[]; myGrid
     // and the space beyond the edge is the theme's own surface (style.css).
     const m = L.map(divRef.current, {
       zoomControl: true, attributionControl: true,
+      // No maxBounds: with the world smaller than the window the clamp
+      // dragged every zoom into a corner. noWrap tiles alone keep one world.
       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);