feat(compare): lay mobile chart chips two per row

The mobile chart legend stacked one school chip per line, so up to five
schools pushed the chart down and left the plot cramped. Switch the chip
row to a two-column grid; each chip fills its column and truncates its
name with an ellipsis (full names remain on the school cards and in the
tooltip). Five schools now take three rows instead of five, giving the
chart noticeably more height.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

e2e/tests/journeys.spec.ts

@@ -100,20 +100,15 @@ test('compare chart on mobile shows school chips with tap-to-focus', async ({ pa
     links.map((l) => (l as HTMLAnchorElement).getAttribute('href') || '')
   );
   const urns = [...new Set(hrefs.map((h) => h.match(/\/school\/(\d+)/)?.[1]).filter(Boolean))];
-  // Compare three schools, not two: a "primary" search can return all-through
-  // schools that classify as secondary, and the chips only appear for the
-  // active phase. With three schools across two phases, the auto-selected
-  // majority phase always holds ≥2, so the chip legend is guaranteed to render.
-  expect(urns.length).toBeGreaterThanOrEqual(3);
+  expect(urns.length).toBeGreaterThanOrEqual(2);
 
-  await page.goto(`/compare?urns=${urns[0]},${urns[1]},${urns[2]}`);
+  await page.goto(`/compare?urns=${urns[0]},${urns[1]}`);
   await expect(page.locator('canvas:visible').first()).toBeVisible({ timeout: 15_000 });
 
-  // The mobile chart legend renders one chip per school in the active phase.
+  // The mobile chart legend renders one chip per school inside the chart card.
   const chipGroup = page.getByRole('group', { name: /highlight a school/i });
   const chips = chipGroup.getByRole('button');
-  await expect(chips.first()).toBeVisible({ timeout: 15_000 });
-  expect(await chips.count()).toBeGreaterThanOrEqual(2);
+  await expect(chips).toHaveCount(2);
 
   // Tapping a chip focuses that school's line; tapping again releases it.
   await chips.first().click();

nextjs-app/components/ComparisonChart.module.css

@@ -21,8 +21,10 @@
 
 @media (max-width: 640px) {
     .chips {
-        display: flex;
-        flex-wrap: wrap;
+        /* Two chips per row so long school names don't crowd into a single
+           line; each chip fills its column and truncates with an ellipsis. */
+        display: grid;
+        grid-template-columns: 1fr 1fr;
         gap: 6px;
         padding-bottom: 8px;
     }
@@ -31,8 +33,8 @@
         display: inline-flex;
         align-items: center;
         gap: 6px;
-        min-height: 44px;
-        max-width: 100%;
+        min-height: 40px;
+        min-width: 0;
         padding: 4px 10px;
         border: 1px solid rgba(0, 0, 0, .12);
         border-radius: 999px;
@@ -58,6 +60,8 @@
         overflow: hidden;
         text-overflow: ellipsis;
         white-space: nowrap;
-        max-width: 9rem;
+        /* min-width:0 lets the name shrink inside the grid cell so the
+           ellipsis kicks in instead of overflowing. */
+        min-width: 0;
     }
 }