Add run pill edge controls

[yvette-carlisle]

Summary

• add fixed endpoint chevrons for overflowing account run pills
• keep single-click alignment to the previous/next pill
• move long-press continuous scrolling to elapsed-time run-loop ticks for smoother pacing
• delay run-pill hover popovers to reduce scroll-time churn

Verification

• swift test --package-path apps/decodex-app
• git diff --check
• cargo make test-decodex-app-stage
• mock Decodex app smoke with 18 active runs: right-arrow click advanced from XY-737 to PUB-738; long press advanced to XY-742/PUB-743/HAST-744