Chart builder: data-aware defaults, one-click hint fixes, canvas preview, fullscreen modal

src/app/stores/ChartBuilderStore.test.ts

@@ -127,6 +127,19 @@ describe('sort / stack', () => {
   });
 });
 
+describe('applyWarningFix', () => {
+  test('applies a hint fix to the working config (actionable hints, §06)', () => {
+    const id = seedDataset('Nums', [
+      { a: 1, b: 2 },
+      { a: 3, b: 4 },
+    ]);
+    cb().init(id);
+    cb().setMark('bar'); // two quantitative axes on a bar → "scatter" hint with a fix
+    cb().applyWarningFix({ label: 'Switch to Point', apply: (c) => ({ ...c, mark: 'point' }) });
+    expect(cb().config.mark).toBe('point');
+  });
+});
+
 describe('createSnippet', () => {
   test('builds a linked snippet, activates it, and resets the builder', () => {
     const id = seedDataset('Sales', [