Add shared Icon primitive and controlled glyph vocabulary (Carbon, filled)

src/app/components/ChartBuilderModal.module.css

@@ -214,14 +214,20 @@
 }
 
 .warning {
+  display: flex;
+  align-items: flex-start;
+  gap: var(--space-2);
   font-size: 12px;
   line-height: 1.4;
   color: var(--text-secondary);
 }
 
-.warning::before {
-  content: '⚠ ';
-  color: var(--support-warning, var(--text-secondary));
+/* Filled status-warning glyph (arch 09 §5.2), in the contrast-safe amber. Replaces
+   the old ⚠ text character so the warning matches the toast status family. */
+.warningIcon {
+  flex: none;
+  margin-top: 1px;
+  color: var(--support-warning-fg);
 }
 
 /* Explains the disabled Create action (contract 10: a disabled control must say