feat(ui): keep bench selects open

BENCH-NOTES.md

@@ -240,3 +240,4 @@
 2026-08-22 09:13 · Reduced the composer underlap to one precedence-ordered status lane, kept terminal interruption with the assistant transcript, and added the three mixed-state sweep fixtures · ui/src/pages/chat/chat-pane-render.ts, ui/src/pages/chat/chat-view.ts, ui/src/pages/chat/components/chat-composer-types.ts, ui/src/pages/chat/components/chat-composer-view.ts, ui/src/pages/chat/components/chat-message-group.ts, ui/src/pages/chat/components/chat-thread-interactions.ts, ui/src/pages/chat/components/chat-transcript-projection.ts, ui/src/pages/chat/components/chat-working-indicator.ts, ui/src/styles/chat/layout.css, ui/src/styles/chat/tool-cards.css, ui/src/test-helpers/composer-bench.ts · COMPONENT #124301 multiline | BENCH
 2026-08-22 09:22 · Matched the Plan hover card to the 600ms open, 300ms close and 100ms fade-scale-slide interaction contract while preserving hover across the card · ui/src/components/session-progress-card.ts, ui/src/styles/chat/progress-card.css · COMPONENT #124301 multiline | BENCH
 2026-08-22 09:31 · Completed queue double-click editing with caret-at-end focus, Enter submit and Escape cancel through the existing inline editor · ui/src/pages/chat/components/chat-composer-queue.ts · COMPONENT #124301 multiline | BENCH
+2026-08-22 09:38 · Kept bench disclosure selects open across live choices and added ArrowUp and ArrowDown selection while retaining header, Escape and outside-click dismissal · ui/src/test-helpers/composer-bench.ts · COMPONENT #124301 multiline | BENCH

ITERATION-NOTES.md

@@ -132,6 +132,7 @@ Local-only working ledger. Re-read after every implementation block; move an ite
 - [x] Add Interrupted + members, offline + read-only and approval + offline sweep fixtures.
 - [x] Match the Plan hover card delays and 100ms fade, scale and upward-slide transition.
 - [x] Complete queue double-click editing with caret-at-end focus, Enter submit and Escape cancel.
+- [x] Keep bench disclosures open while selecting and support live ArrowUp and ArrowDown changes.
 
 ## Observed queue contract
 

ui/src/test-helpers/composer-bench.ts

@@ -2077,6 +2077,22 @@ benchDisclosures.forEach((disclosure) => {
       if (other !== disclosure) other.open = false;
     });
   });
+  disclosure.addEventListener("keydown", (event) => {
+    if (!disclosure.open || !["ArrowUp", "ArrowDown"].includes(event.key)) return;
+    const options = [
+      ...disclosure.querySelectorAll<HTMLButtonElement>(
+        "[data-bench-axis][data-bench-value]:not(:disabled)",
+      ),
+    ];
+    if (options.length === 0) return;
+    event.preventDefault();
+    const activeIndex = options.findIndex((option) => option.hasAttribute("data-active"));
+    const direction = event.key === "ArrowUp" ? -1 : 1;
+    const nextIndex = (Math.max(activeIndex, 0) + direction + options.length) % options.length;
+    const nextOption = options[nextIndex];
+    nextOption?.click();
+    nextOption?.focus({ preventScroll: true });
+  });
 });
 document.addEventListener("pointerdown", (event) => {
   const target = event.target;