[wangbinyq]

What

On a phone, the schedule picked in Running now shows under the session names that the Coming up timeline pins at its left.

Why

The picked schedule's card is .board-bar, z-index: 3. Each timeline lane's name is .rb-lane-name, position: sticky; left: 0; z-index: 4, so it stays at the timeline's left while the timeline pans. Both sit in the same stacking context, so 4 paints over 3: the name, with its opaque --card background, cuts across the card.

.board-bar now takes z-index: 5: above the pinned names, below the timeline tip (.rb-tip, z-index: 50) and the app's overlays (45 and up).

Before and after

390×560, real Chrome, a session with a /schedule message, one pin tapped. The red boxes mark the lane names that paint over the card:

Before	After

Tested

• test/running-board-stack.test.ts reads web/style.css and asserts the bar outranks the pinned lane name, and the tip outranks the bar. It fails before the change (3 > 4 is false) and passes after.
• Ran the branch locally at 390×560, made five sessions each with a /schedule message, opened Running now, and tapped a pin. With z-index: 3 the script counted three lane names painting over the card; with 5 it counted none. The two screenshots above are that run.
• npm run check, npm run lint, npx prettier --check web/style.css test/running-board-stack.test.ts.
• npm test: five failures, in design-lint-pages, design-render, design-verify, and watch-tree. The same five fail on HEAD~1 in this environment, and none of them reads web/style.css.