Restyle the board view

[aksOps]

Question

Migrate the board to the spec: shade-tier depth, column header bands (Raised tier, solid hue on focus), borderless cards with priority rails (thicken on selection, keep hue), title + muted description snippet per the card anatomy spec, pill-capped chips, zebra at compact density, both-axis compaction (height < 30 or inner width < 22; tune the 22 with a 60x50 golden), filter bar and status/footer bands. Remove board_view.go's inline styles via the theme seam.

The binding spec is docs/design/tui-design-spec.md on branch design/tui-spec (resolution of #139). Read it before writing any code; deviations must be deliberate and recorded on the map.

Execution protocol: map #80 rules (claim by self-assignment, branch from origin/main, PR, squash-merge on green with acceptance checked, resolution comment, close, append one line to map #136). Coverage: 96.4% total / 95% per package / 90% floor for internal/tui. Color goldens pin tea.WithColorProfile; regenerate goldens touched by the restyle in the same PR.

Part of #136.

Blocked by: #140

[aksOps]

Resolved by #148 (squash-merged as 9cfed54).

The board is on the theme and widget seam: shade-tier depth end to end (Canvas page ground, Surface panels and footer, Card/Zebra/Raised card surfaces), borderless column panels with header bands that fill solid with the column hue on focus, borderless cards with a priority rail that thickens on selection and keeps its hue, title plus a muted description snippet, pill-capped meta chips and label pills, zebra striping and both-axis compaction (h<30 or inner<22), and a restyled filter bar and status band. board_view.go builds no lipgloss style any more - its priority, chip, label and status hexes are deleted - and its seam allowlist entry is gone with them.

Goldens: TestEmptyBoardGolden regenerated, TestBoardCardsColorGolden added pinned to truecolor per spec section 6.4, and TestNarrowTallBoardGolden added as the 60x50 capture this ticket asked for. That capture is also the answer on the width axis: below the wide-frame threshold kb shows a single column that MaxColumnWidth holds at 52, so 60x50 never approaches the threshold. It fires between frame widths 100 and ~116 where four columns share the frame - card inner 23 at 120, 18 at 100 - so 22 was left at the spec's value.

Interaction is unchanged. Every behavioral test passes unmodified except where it asserted on rendering; four tests moved a coordinate because the layout moved (one more chrome row for the page padding, and the column group is centered).

Deviations, all recorded on the PR and on map #136: the top bar, filter bar and footer keep their v1.0.1 text vocabulary and are restyled by tier and hue only, because their click regions are keyed to plain-text widths; no status dot in the footer; the lifted card drops its arrow marker; widget.CardWithSpans and theme.Glyphs.Blocked added; carddetail.Model.SetStyles added so the panes adopt the palette the root rebuilds.