feat(canvas): add persistent node favorites with toolbar star and glow

app/globals.css

@@ -81,6 +81,9 @@
   --sidebar-accent-foreground: oklch(0.25 0.012 60);
   --sidebar-border: oklch(0.91 0.01 75);
   --sidebar-ring: oklch(0.52 0.09 178);
+  --node-favorite-ring: oklch(0.72 0.16 88);
+  --node-favorite-glow: oklch(0.78 0.18 90 / 0.24);
+  --node-favorite-fill: oklch(0.93 0.08 92 / 0.45);
 }
 
 .dark {
@@ -115,6 +118,9 @@
   --sidebar-accent-foreground: oklch(0.93 0.008 80);
   --sidebar-border: oklch(1 0 0 / 8%);
   --sidebar-ring: oklch(0.62 0.1 178);
+  --node-favorite-ring: oklch(0.84 0.14 92);
+  --node-favorite-glow: oklch(0.82 0.16 92 / 0.36);
+  --node-favorite-fill: oklch(0.48 0.12 90 / 0.28);
 }
 
 @layer base {
@@ -306,4 +312,21 @@
       transition: none;
     }
   }
+
+  .node-favorite-chrome {
+    position: relative;
+    isolation: isolate;
+  }
+
+  .node-favorite-chrome::after {
+    content: "";
+    position: absolute;
+    inset: -1px;
+    border-radius: inherit;
+    pointer-events: none;
+    box-shadow:
+      0 0 0 1px var(--node-favorite-ring),
+      0 0 0 3px var(--node-favorite-fill),
+      0 0 22px -8px var(--node-favorite-glow);
+  }
 }