Ensure SVG styles don't escape containment

src/ui/res/img/alignment-indicators.svg

@@ -1,4 +1,4 @@
-<svg width="90" height="90" viewBox="0 0 90 90" xmlns="http://www.w3.org/2000/svg">
+<svg id="_uw_ui_alignment_indicator" width="90" height="90" viewBox="0 0 90 90" xmlns="http://www.w3.org/2000/svg">
   <defs>
     <!-- Glow filter for selected symbol -->
     <filter id="glow" x="-50%" y="-50%" width="200%" height="200%">
@@ -7,31 +7,31 @@
   </defs>
 
   <style>
-    path {
-      /*fill: oklch(86.9% 0.005 56.366)*/;
+    /* Default path color and transition */
+    #_uw_ui_alignment_indicator path {
       fill: oklch(55.3% 0.013 58.071);
       transition: fill 0.2s, filter 0.2s;
     }
 
-    rect.indicator-bg {
+    /* Default background for squares */
+    #_uw_ui_alignment_indicator rect.indicator-bg {
       fill: transparent;
       transition: fill 0.2s;
     }
 
-    /* Hover */
-    g:hover path {
+    /* Hover state */
+    #_uw_ui_alignment_indicator g:hover path {
       fill: #fff;
     }
-    g:hover rect.indicator-bg {
+    #_uw_ui_alignment_indicator g:hover rect.indicator-bg {
       fill: oklch(37.4% 0.01 67.558);
     }
-
-    g:hover {
+    #_uw_ui_alignment_indicator g:hover {
       cursor: pointer;
     }
 
     /* Selected state: white + glow */
-    g.selected path {
+    #_uw_ui_alignment_indicator g.selected path {
       fill: #fff;
       filter: url(#glow);
     }