Task Ledger CSS still describes the retired nested task row #4394

Problem

#4351 retired the Task Ledger demand chain and replaced it with the Host-owned, flat SessionTodo document. packages/ui/src/task-ledger-panel.tsx became packages/ui/src/session-todo-panel.tsx, which renders each item as:

<li className="maka-task-ledger-row" key={...}>
  <StatusIcon size={ICON_SIZE.control} aria-hidden="true" />
  <span>{item.content}</span>
</li>

Only the class names carried over. The stylesheet apps/desktop/src/renderer/styles/task-ledger.css was not updated with it, so it still describes the retired nested, four-column row. The new panel uses only maka-task-ledger-panel, -message, -retry, -empty, -tree, and -row; it never sets data-status, never sets --task-depth, and has no role="group" descendants.

Rules on main that can no longer match anything:

• :35 — grid-template-columns: 14px minmax(34px, auto) minmax(100px, 1fr) auto. The row has two children, so two of the four columns are always empty.
• :39 — the --task-depth indent. The custom property is never set, so it silently resolves to the no-indent case.
• :44 — .maka-task-ledger-group. No element carries this class.
• :56-59 — the four .maka-task-ledger-row[data-status="…"] > svg rules. data-status is never set.
• :61-80 — .maka-task-ledger-key, -subject, -meta, -detail. None of these classes are rendered.
• :131-134 — the @media (max-width: 620px) block, which only restyles -row, -meta, and -detail.

There is no user-visible defect: unmatched selectors do nothing. The cost is that the stylesheet misdescribes the component, so the next person to touch this panel reads a four-column nested tree contract that does not exist.

Desired outcome

task-ledger.css describes what SessionTodoPanel actually renders. Deleting the rules listed above and reducing the row styling to what the flat <li> needs is the whole change.

One thing to preserve rather than delete outright: the @media (max-width: 620px) block is keyed off the viewport, but the right workbar resizes down to SESSION_WORKBAR_MIN_WIDTH (320px) inside an otherwise wide window, where a viewport query never fires. That mismatch is independent of the removed nesting. If any width-responsive behavior is kept for this panel, it should be an @container query on .maka-task-ledger-panel, matching the existing inspector.css and chat-header.css precedent. Credit to @liuxiaocs7, who identified and implemented this in #4215 before that PR was superseded.

Renaming the file and the maka-task-ledger-* class prefix to match SessionTodoPanel is probably worth folding in, but that is a judgement call for whoever picks this up.

Verify with the existing Storybook coverage for the tasks panel (Tasks, TasksEmpty, TasksLoadFailed) rather than adding new tests — the change should be visually inert.

Alternatives or workarounds

Leaving it costs nothing at runtime. The reason to do it now is that the stylesheet is currently misleading documentation of a component it no longer matches, and the cost of removal only grows as more rules accumulate around the dead ones.

Additional context

Found while reviewing #4215, which is superseded by #4351 for the same reason.

Analysis produced with Claude Code and verified against main.