Fix spinner z-index to appear above Plotly plot

Increase umapSpinner z-index from 1000 to 10000 to ensure it appears above the Plotly plot content. Also add pointer-events: none to allow clicks to pass through the spinner container.

The issue was that the spinner and the UMAP window had the same z-index (1000), causing the Plotly plot elements to render above the spinner.

Fixes comment from @lstein about spinner not appearing.

Co-authored-by: lstein <111189+lstein@users.noreply.github.com>

Author: Copilot

photomap/frontend/static/css/spinners.css

@@ -16,7 +16,8 @@
   left: 50%;
   top: 50%;
   transform: translate(-50%, -50%);
-  z-index: 1000;
+  z-index: 10000;
+  pointer-events: none;
 }
 
 #umapSpinner .umap-spinner {

photomap/frontend/templates/modules/umap-floating-window.html

@@ -117,7 +117,8 @@
       left: 50%;
       top: 50%;
       transform: translate(-50%, -50%);
-      z-index: 1000;
+      z-index: 10000;
+      pointer-events: none;
     "
   >
     <div class="umap-spinner"></div>