Board: drag handle is not vertically aligned with BoardItemTitle #71

Problem

Board's drag handle does not line up with the item's title. On backend.ai-webui's dashboard, every board item renders a BoardItemTitle as its first row (via BAIBoardItemTitle), and in edit mode the grip glyph sits in the card's top-left corner, above the title text, so the two never share a line.

Reported from the WebUI side as lablup/backend.ai-webui#10365, which stays open until webui adopts a ui-common release with the fix.

Cause

Board draws only the item shell and the handles; the title row is the consumer's, placed inside renderItem. The two are positioned independently:

• src/components/Board/Board.css: .uic-board-item__handle--drag is absolutely positioned at inset-block-start: var(--spacing-2) from the item's top.
• src/components/BoardItemTitle/BoardItemTitle.css: .uic-board-item-title pads its row with padding-block: var(--spacing-5).

Measured in Storybook (Components/Board → Editable, Playwright, with the story wrapper's block padding removed so the title row starts at the item's top, as on the webui dashboard): the sm handle (28px) is centered 12px above the title row's center.

Proposal

Make the title the board's, not the consumer's, and drop renderItem: an item is its title and description, both padded by the board, and the drag handle sits in that padding on the title row's first line.

Props

Added on BoardItem:

Added on BoardProps:

Removed: renderItem, BoardItemActions / removeItem, removedItem, liveAnnouncementItemRemoved, the uic.Board.itemRemoved key. Removing an item is the consumer's: pass items without it. BoardItemTitle becomes a plain title node (no own padding, not sticky).

Rendering

.uic-board-item
├─ drag handle                 (absolute; top offset = the top padding, left --spacing-1)
├─ .uic-board-item__header     (only with a title; padding = the item's)
│    [title: heading or node; first line centered on the handle, the rest wrap below]
├─ .uic-board-item__content    (description; padding = the item's, no top padding after a header; scrolls)
└─ resize handle               (absolute, bottom-end, unchanged)

Consumer migration (backend.ai-webui)

• BAIBoard passes title / description and itemPadding through instead of defaulting renderItem to data.content.
• Dashboard panels split into a title node (BAIBoardItemTitle with the refresh button and edit controls) and a body, and drop their own inline inset.
• Start page tiles pass description only.

Status of #68

#68 carries this design.