Collapsible status groups in plan sidebar

Acceptance Criteria

• Sidebar items are grouped by status within each entity type
• Groups are collapsible via click on the group header
• Terminal statuses (done, fixed, accepted, complete, superseded, deprecated, wontfix, duplicate) are collapsed by default
• Active statuses (in-progress, ready, review, confirmed) are expanded by default
• Each group header shows a count badge (e.g., "In Progress (3)")
• Status ordering follows workflow progression (active statuses first)
• Collapse state persists across page navigation via localStorage
• Works in both serve and build modes

Approach

The server renders the full grouped structure with data attributes. A client-side behavior (either in @refrakt-md/behaviors or plan-specific) adds toggle controls and manages collapse state. The nav region builder (WORK-038) emits the grouped structure.

References

• Plan Site UX at Scale (Plan Site UX at Scale — Feature 1)
• Build nav region builder for plan site (nav region builder — emits the structure this behavior enhances)
• Refactor plan render pipeline to use @refrakt-md/html (HTML adapter refactor — prerequisite infrastructure)