Fix note UX: unreachable wiki link, white Save hover, stale icon preview, invisible new points

- "Nearby on Wikipedia" linked to KIWIX_URL, a Docker-internal hostname
  (http://kiwix:8080) no real browser can resolve. Split it: KIWIX_URL
  stays server-side-only for the reachability check, and the link
  itself is built from KIWIX_PUBLIC_PORT (kiwix-serve's newly
  published host port) plus whatever host the visitor already used to
  reach maptool — works regardless of which hostname/IP that is.
- The Save button went white on hover in GTK-themed Chrome: the
  browser's native button skin was painting over the custom
  background because appearance wasn't reset.
- The map preview marker for a pending note always showed a plain red
  pin no matter which icon was picked in the form. NoteSaveForm now
  reports icon changes via onIconChange so NotesControl can update the
  marker's glyph live.
- Saving a note (or a Measure "Save as note") left the new/grown
  .geojson file unchecked and invisible until manually toggled on.
  notifyGpxStoreChanged now carries the affected path so
  GpxPanelControl auto-shows it.

public/js/panels.js

@@ -18,13 +18,16 @@ export function onlyOneSidePanelOpen(panel, onClosedByOther) {
 
 // Lets a control that writes into the GPX store (e.g. notes.js saving a
 // drawn point) tell GpxPanelControl its tree is stale, without either one
-// holding a reference to the other.
+// holding a reference to the other. path (the .geojson file just written
+// to) lets the listener also auto-show that file instead of just refreshing
+// the tree — the point/shape just saved is otherwise invisible until the
+// user finds and checks it by hand.
 const STORE_CHANGED_EVENT = "gpx-store-changed";
 
-export function notifyGpxStoreChanged() {
-  document.dispatchEvent(new CustomEvent(STORE_CHANGED_EVENT));
+export function notifyGpxStoreChanged(path) {
+  document.dispatchEvent(new CustomEvent(STORE_CHANGED_EVENT, { detail: path }));
 }
 
 export function onGpxStoreChanged(callback) {
-  document.addEventListener(STORE_CHANGED_EVENT, callback);
+  document.addEventListener(STORE_CHANGED_EVENT, (event) => callback(event.detail));
 }