Stop the test runner tripping the rate limiter, and level the rows

The end-to-end suite had never been run. Its first run failed six ways,
all of them the page sitting on the login screen: every browser page load
re-obtains an access token, the refresh endpoint allows thirty a minute
per address, and a twenty-test run makes about fifty of them from one
address. Half came back 429, and a failed refresh is indistinguishable
from being logged out. Raising the ceiling would only move it and make a
green suite depend on how fast the machine is, so the limiter is switched
off for the test backend alone — it measures a client, and the runner is
not one. It stays on everywhere else.

With that gone, one real failure was left, and it belonged to the commit
that claimed to have fixed it: cell widths were held, but a week whose
cell carries a holiday name still stood taller than its neighbours,
because each week is its own grid and none can see another's height. The
weeks now share one grid whose rows are all a single fraction, so the
tallest sets the rest and no cell can grow its own row.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ei7gCZzdd751uZtPzb1Pep

frontend/src/pages/Calendar.test.tsx

@@ -1793,6 +1793,18 @@ describe('Calendar', () => {
       expect(css).toMatch(/\.calendar-day\s*{[^}]*min-width:\s*0/)
       expect(css).toMatch(/\.calendar-week__day-cell\s*{[^}]*min-width:\s*0/)
       expect(css).toMatch(/\.calendar-day__holiday-name\s*{[^}]*min-width:\s*0/)
+
+      // The height half of the same invariant. Each `.calendar-week` is its
+      // own grid container, so a cell carrying an extra line (the holiday
+      // name) grew only ITS row — October 2026's last row rendered 3.5px
+      // taller than the other four. `.calendar__weeks` is therefore a grid
+      // with `grid-auto-rows: 1fr`, which on an auto-height container sizes
+      // every row to the tallest one. jsdom does no layout, so this can only
+      // be asserted against the stylesheet text, exactly like the width
+      // rules above — `e2e/tests/calendar-grid-uniform.spec.ts` is what
+      // measures it in a real browser.
+      expect(css).toMatch(/\.calendar__weeks\s*{[^}]*grid-auto-rows:\s*1fr/)
+      expect(css).toMatch(/\.calendar__weeks\s*{[^}]*grid-template-columns:\s*minmax\(0,\s*1fr\)/)
     })
 
     it('reserves the same --band-reserved-height on every week row, even though only one week has a band', () => {