design(board): tighten list row vertical rhythm on desktop

[johnpc]

Design-polish pass — continuing on the List view (per owner direction). Measuring the row density (harness read boundingBox + computed padding), the chip-less single-line rows were airy — ~44px each — so the list felt loose and fewer tasks were scannable at once than in Asana's denser list.

Fix (CSS-only, tokens only)

Reduced the list row vertical padding from 8px to 6px. Chip-carrying rows still grow with their content (labels, subtask counts) — only the airy single-line rows tighten up. At 1280×800 this fits ~11 rows instead of ~10, and a single-line row drops from ~62px to ~58px, so the list reads as a crisp scannable table without feeling cramped.

Mobile is unaffected: the @media (max-width: 600px) stacked-row layout keeps its own roomier 12px padding (appropriate for touch targets).

Before → after

• Desktop (tighter, ~11 rows visible): https://files.jpc.io/d/WDOIC-list-density-after-desktop.png

Full quality gate green; presentational-only. Verified against the sandbox (AWS_PROFILE=personal).