design(mytasks): render tasks as a dense ruled list, not floating cards

[johnpc]

What

My Tasks — a primary tab — rendered each task as a full-width floating board card (border + drop-shadow + radius, gap: 8px between them). Because My Tasks is a single vertical column, that produced tall cards with the title + a couple of small chips clustered in the left third and a large empty right region on desktop, and airy, low-density rows on mobile. It read as a loose stack of cards, not a task list.

This applies the same dense ruled-table treatment the List view already uses (#109), scoped to .mytasks__row:

• Strip the board card's border / box-shadow / border-radius / surface fill from the card only inside a My Tasks row — the board and its cards are untouched.
• Give each row a single border-bottom hairline (--tf-border) + a --tf-surface-2 hover highlight, and zero the inter-row gap so the dividers butt into one continuous ruled list.
• Tighten row padding (10px → 8px 6px) so more tasks are scannable above the fold.

Token/CSS-only; no markup, logic, or schema change. Scoped to .mytasks__row / .mytasks__row > .task-card.

Before / After

Desktop

Before	After

Mobile

Before	After

After: rows read as a clean dense list — hairline dividers, no empty right region, more tasks visible per screen.