Project · Issues and boards: a board, issue cards, a task's panel, labels

KanbanBoard lays columns of cards side by side. A card drags to a
place in any column: it rides raised at the pointer, a slot opens where
it would land, the other cards glide aside on motion::Flip, and the
drop asks the owner through on_move(card, column, index); a drop in its
own place asks nothing. Option with an arrow moves the focused card,
whose focus the board keys by card so it follows it across columns. A
press, Enter or Space opens it. Sprint Board is this board.

IssueCard shows an issue's status, name, assignee, title, priority,
labels and due day. TaskDetailPanel lays a task out in full: its title
edits in place, its status, priority, assignee and due day change where
they stand, and its notes and steps follow; each edit hands the whole
task on, and a blank title is not taken. LabelManager tends a team's
labels: a hue picked from a popover, a name edited in place, a delete,
and a field that makes a new one; names stay unique in any case, and a
refused name says why.

The fill rule changes: min_w_full, taken up in T30d, resolves against
a block's outer width in taffy 0.9, so a field in a padded card ran
past its padding. A component that fills now takes no width on its
root, which blocks and flex columns stretch; FormField and the new
roots do. The chart's hue names move to theme::HUE_NAMES, which the
event editor and the label manager share.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tasks/ch31-43.md

@@ -13,11 +13,11 @@
 
 ## T31b Project · Issues and boards
 
-- [ ] IssueCard
-- [ ] LabelManager
-- [ ] KanbanBoard / KanbanColumn / KanbanCard
-- [ ] Sprint Board → `project::KanbanBoard`
-- [ ] TaskDetailPanel
+- [x] IssueCard
+- [x] LabelManager
+- [x] KanbanBoard / KanbanColumn / KanbanCard
+- [x] Sprint Board → `project::KanbanBoard`
+- [x] TaskDetailPanel
 
 ## T31c Project · Plans