Motir

Surface SPRINT membership directly on the work-item detail (it's only assignable from the backlog (4.2) / board / MCP today). Two additions, both reusing existing patterns:

1. Sprint as an inline-editable field. Show Sprint alongside the other detail fields (assignee / priority / type / estimate) and make it inline-editable — a sprint picker (the shipped Combobox) listing the project's sprints (+ Backlog / none) that changes membership in place, exactly like the other inline fields. Uses the existing assign-to-sprint service (4.2 / move_to_sprint).
2. 3-dots menu → 'Add to active sprint'. A quick action in the work-item overflow (3-dots) menu that one-click assigns the item to the project's currently-active sprint (4.4 lifecycle). Grey it out / disable when there is no active sprint, with a tooltip ('No active sprint') so the reason is clear.

Reuse the established inline-edit field grammar + the existing 3-dots menu pattern — no new design vocabulary (sprint picker = Combobox; menu item = the existing action grammar). Honour the page-state-after-mutation contract: changing the sprint updates the field's own cell (optimistic, no tree refresh) AND any sprint-dependent surface on the page.

Acceptance criteria

• The detail shows the current Sprint (or 'Backlog') and lets you change/clear it inline; the change persists (waitForResponse on the assign call) and the cell keeps the optimistic value.
• The 3-dots menu shows 'Add to active sprint'; it assigns to the active sprint when one exists, and is disabled with a tooltip when none is active.
• A no-active-sprint project shows the disabled state; an active-sprint project assigns correctly.
• E2E covers inline change + the 3-dots quick action (active + no-active states).

Context refs

• 2.4 Issue detail view (the fields panel + the 3-dots menu)
• 4.2 Backlog UI / assignToSprint service · move_to_sprint (the underlying capability)
• 4.4 Sprint lifecycle (the 'active sprint' concept)
• the shipped inline-edit field pattern (assignee/priority) + Combobox