* feat: add work item state duration endpoint Add a new endpoint to compute time spent between state transitions for a work item by filtering state-change activities and calculating the duration from the previous boundary to each transition. Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]> * feat: add state duration type and service method * feat: add state duration store support * feat: add badge slot to PropertyValue in transition row * feat: add DurationBadge component with color tiers and tooltip * feat: display state duration badges in transition activity tab * feat: add appendElement prop to state dropdown * feat: show state duration badge in detail sidebar and peek overview * feat: fetch state duration on page load and revalidate on socket events * chore: code refactoring * chore: code refactoring --------- Co-authored-by: sriramveeraghanta <[email protected]> Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>