Chart builder: discoverable entry points — Build Chart door, dataset picker, no-datasets state

src/app/components/Icon.tsx

@@ -27,6 +27,7 @@ export type IconName =
   | 'dataset' // "references a dataset" — Carbon DataTable
   | 'delete' // delete — Carbon TrashCan
   | 'add' // add / create-new — Carbon Add
+  | 'chart' // build / open a chart — rising columns on a baseline (pane-icon style)
   | 'search' // live library search — Carbon Search
   | 'settings' // per-pane settings disclosure (gear) — Carbon Settings
   | 'import' // import a workspace file — Carbon Upload (a file goes in)
@@ -55,6 +56,16 @@ const GLYPHS: Record<IconName, ReactNode> = {
     <polygon points="17.4141 16 24 9.4141 22.5859 8 16 14.5859 9.4143 8 8 9.4141 14.5859 16 8 22.5859 9.4143 24 16 17.4141 22.5859 24 24 22.5859 17.4141 16" />
   ),
   add: <polygon points="17,15 17,8 15,8 15,15 8,15 8,17 15,17 15,24 17,24 17,17 24,17 24,15" />,
+  // Rising columns on a baseline — drawn in the pane-icon rect style (not a Carbon
+  // trace) so it reads at 16px next to the pane glyphs.
+  chart: (
+    <>
+      <rect x="4" y="24" width="24" height="2" />
+      <rect x="8" y="16" width="4" height="8" />
+      <rect x="14" y="10" width="4" height="14" />
+      <rect x="20" y="6" width="4" height="18" />
+    </>
+  ),
   // Carbon Search — magnifying glass, the active-search affordance (council SEARCH).
   search: (
     <path d="M29,27.5859l-7.5521-7.5521a11.0177,11.0177,0,1,0-1.4141,1.4141L27.5859,29ZM4,13a9,9,0,1,1,9,9A9.01,9.01,0,0,1,4,13Z" />