Fix mobile detail panel height to account for browser chrome (THE-188)

Use 100dvh (dynamic viewport height) instead of 100vh so the panel
footer with "Report an Issue" buttons is accessible on mobile browsers
where the address bar and navigation bar reduce visible viewport height.
Falls back to 100vh for older browsers.

Also enable pointer-events on the panel overlay on mobile so tapping
outside the panel closes it.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

public/css/panel.css

@@ -21,6 +21,7 @@
   right: 0;
   width: 340px;
   height: 100vh;
+  height: 100dvh;
   background: var(--color-surface);
   border-left: 1px solid var(--color-border);
   box-shadow: var(--shadow-md);
@@ -458,9 +459,14 @@
   #tool-panel {
     width: 100vw;
     height: 100vh;
+    height: 100dvh;
     top: 0;
     right: 0;
     border-left: none;
     border-radius: 0;
   }
+
+  #panel-overlay.visible {
+    pointer-events: auto;
+  }
 }