master
feat: major UI overhaul — multi-doc assembly workflow, preview enhancements, zoom controls
feat: add manual assembly, apply bug fixes (base_bar_angle, temp file cleanup, md5, db connection)
refactor(manual_assembly): replace Treeview with Canvas for full-page preview
refactor: Complete ESKD archive system - rewrite append_document, fix typos, enhance UL generator, add date masking, and improve PDF preview engine
refactor: migrate modules to src/, add logging system, add assembly workshop
