fix: align sidebar filter titles

tests/catalog.spec.ts

@@ -136,6 +136,46 @@ test('desktop filter rail scrolls independently from the catalog page', async ({
   expect(metrics.listScrollbarColor).not.toBe('auto');
 });
 
+test('sidebar filter titles sit inside their panels', async ({ page }) => {
+  await page.setViewportSize({ width: 1280, height: 720 });
+  await page.goto('/');
+
+  const panelMetrics = await page.locator('.filter-panel').evaluateAll((panels) =>
+    panels
+      .map((panel) => {
+        const legend = panel.querySelector('legend');
+        if (!legend) return null;
+
+        const panelBox = panel.getBoundingClientRect();
+        const legendBox = legend.getBoundingClientRect();
+        const styles = window.getComputedStyle(panel);
+
+        return {
+          title: legend.textContent?.trim(),
+          panelTop: panelBox.top,
+          panelLeft: panelBox.left,
+          legendTop: legendBox.top,
+          legendLeft: legendBox.left,
+          paddingTop: Number.parseFloat(styles.paddingTop),
+          paddingLeft: Number.parseFloat(styles.paddingLeft),
+        };
+      })
+      .filter(Boolean),
+  );
+
+  expect(panelMetrics).toEqual(
+    expect.arrayContaining([
+      expect.objectContaining({ title: 'Platform' }),
+      expect.objectContaining({ title: 'Base' }),
+    ]),
+  );
+
+  for (const metrics of panelMetrics) {
+    expect(metrics!.legendTop).toBeGreaterThanOrEqual(metrics!.panelTop + metrics!.paddingTop - 1);
+    expect(metrics!.legendLeft).toBeGreaterThanOrEqual(metrics!.panelLeft + metrics!.paddingLeft - 1);
+  }
+});
+
 test('detail page renders metadata and private file links', async ({ page }) => {
   await page.goto('/hack/radical-red/');