Retry failed Firefox and WebKit tests once

AGENTS.md

@@ -45,6 +45,7 @@ website/              # demo site (Vite + TanStack Router)
 - Browser tests use `vite-plus/test/browser` + Playwright. `test/setupBrowser.ts` configures `page.render()` via `vitest-browser-react` and registers custom locators via `locators.extend()` — prefer `page.getGrid()`, `page.getCell({ name })`, `page.getRow()`, `page.getHeaderCell()`, `page.getActiveCell()`, etc. over raw `page.getByRole()`.
 - Test helpers in `test/browser/utils.tsx`: `setup()`, `getRowWithCell()`, `getCellsAtRowIndex()`, `validateCellPosition()`, `scrollGrid()`, `safeTab()`, `testCount()`, `testRowCount()`.
 - `test/failOnConsole.ts` fails tests on unexpected console warnings/errors.
+- Firefox and WebKit retry failed tests once (`retry` in `vite.config.ts`), and `--retry=0` doesn't override it. Add `--reporter=verbose` to see tests that passed on retry, marked `(retry x1)`.
 - **Never run visual regression tests** — screenshots are environment-dependent, so visual regression tests must run in CI only.
 
 ## Tooling

vite.config.ts

@@ -60,6 +60,10 @@ async function getTscPath(): Promise<string> {
 
 const actionTimeout = 2000;
 const viewport = { width: 1920, height: 1080 } as const;
+// Firefox and WebKit tests are flakier than Chromium tests, so they retry failed tests once.
+// Chromium doesn't retry, so flakes caused by the grid itself still fail there.
+// On GitHub Actions, the job summary lists tests that passed on retry.
+const retry = 1;
 const playwrightOptions: PlaywrightProviderOptions = {
   actionTimeout,
   contextOptions: {
@@ -299,11 +303,13 @@ export default defineConfig({
             }
           }),
           // TODO: remove when FF tests are stable
-          fileParallelism: false
+          fileParallelism: false,
+          retry
         },
         {
           browser: 'webkit',
-          provider: playwright(playwrightOptions)
+          provider: playwright(playwrightOptions),
+          retry
         }
       ]
     },