Completes the CSV Integration and Field Mapping epic by collapsing blank
optional address lines (with a visual distinction between blank data and a
mapping error), and delivers text/field rotation end-to-end: a free-form
angle property that rotates about the element's bounding-box center
(verified against the real Debenu DLL with a pixel-centroid regression
test), plus an interactive drag-to-rotate canvas handle. Closes out Sprint 4
with review and retrospective notes, including resolving the prior
retrospective's product-owner review-independence watch item. Also captures
requirements (not yet sized) for a new composite Address Control epic.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>