sea-select deal FT: scroll the revealed FLIP btn into view before the is_displayed assert — TDD

test_clicking_stack_shows_ok_btn is the only PickSeaDealTest that pairs _choose_spread w. an is_displayed() assert (the six-draws test checks the class instead). Once a spread is OK'd the felt scroll-snaps onto two pages + the deck stacks sit on the page the post-OK rAF scroll-to-cross targets — but headless Firefox DROPS that delayed scroll, leaving the clicked stack's revealed FLIP btn off the visible page → is_displayed False. scrollIntoView the btn first so the assert reflects the `--active` reveal, not the scroll position. Surfaced in CI build 374's channels stage (a flake that 373 survived on retry; my bd9155c preview edits only shifted the timing).

[[feedback-headless-delayed-scroll-dropped]]

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/functional_tests/test_game_room_select_sea.py

@@ -301,7 +301,16 @@ class PickSeaDealTest(ChannelsFunctionalTest):
         ok_btn = self.wait_for(lambda: self.browser.find_element(
             By.CSS_SELECTOR, ".sea-deck-stack--levity .sea-stack-ok"
         ))
-        self.assertTrue(ok_btn.is_displayed())
+        # Choosing the spread scroll-snaps the felt onto two pages; the deck
+        # stacks sit on a different page than the post-OK scroll lands on in
+        # headless (the rAF scroll-to-cross is dropped, see
+        # [[feedback-headless-delayed-scroll-dropped]]), leaving the revealed OK
+        # btn off the visible page. Pull it into view so is_displayed reflects
+        # the `--active` reveal, not the scroll position.
+        self.browser.execute_script(
+            "arguments[0].scrollIntoView({block: 'center'})", ok_btn
+        )
+        self.wait_for(lambda: self.assertTrue(ok_btn.is_displayed()))
 
     def test_clicking_elsewhere_hides_ok_btn(self):
         """Clicking outside a focused stack dismisses the OK btn."""