fix: always add tile layer at map init, fix zoom bounds

- tiles.addTo(map) now called at init instead of lazily on first trip click
  (fixes blank map on page load on the server portal)
- minZoom/maxZoom read from data-min-zoom/data-max-zoom attributes with
  correct NaN fallback (parseInt || default)
- Pi template: data-min-zoom=8 data-max-zoom=15 (matches cached tile range)
- Server template: data-min-zoom=3 data-max-zoom=19 (full OSM range)

Co-authored-by: Copilot <[email protected]>

static/js/history.js

@@ -13,14 +13,14 @@
     const mapEl = document.getElementById("history-map");
     const tileUrl = mapEl.dataset.tileUrl || "/static/vendor/tiles/{z}/{x}/{y}.png";
     const tileAttrib = mapEl.dataset.tileAttrib || "© MapTiler © OpenStreetMap contributors";
-    const minZoom = parseInt(mapEl.dataset.minZoom || "3", 10);
-    const maxZoom = parseInt(mapEl.dataset.maxZoom || "19", 10);
-    const map = L.map("history-map", { minZoom, maxZoom }).setView([48.505, -0.09], 12);
+    const minZoom = parseInt(mapEl.dataset.minZoom, 10) || 3;
+    const maxZoom = parseInt(mapEl.dataset.maxZoom, 10) || 19;
+    const map = L.map("history-map", { minZoom: minZoom, maxZoom: maxZoom }).setView([48.505, -0.09], 12);
     const tiles = L.tileLayer(tileUrl, {
-        minZoom,
-        maxZoom,
+        minZoom: minZoom,
+        maxZoom: maxZoom,
         attribution: tileAttrib,
-    });
+    }).addTo(map);
     let routeLayer = null;
     let vehicleMarker = null;
     let replayPoints = [];
@@ -147,9 +147,6 @@
         if (routeLayer) {
             routeLayer.remove();
         }
-        if (!map.hasLayer(tiles)) {
-            tiles.addTo(map);
-        }
         const coordinates = result.points.map(function (point) {
             return [point.latitude, point.longitude];
         });