Add a 'Copy from existing' option to the New Canvas modal. It lists every
canvas with node/group/text counts; picking one deep-copies its nodes, edges,
parent/child links and canvas state (viewport, custom style, floor plan) into
a fresh design.
Backend: POST /designs/{source_id}/copy remaps node ids, re-points edges and
parent links, and clones canvas state; GET /designs now returns per-design
counts for the picker. Standalone mode clones the localStorage canvas.
Closes#216
ha-relevant: maybe
Make designs (canvases) fully user-manageable: create with a chosen name
and icon, rename, change icon, and delete. Replaces the hardcoded
"New Electrical Design" button with a generic "New Canvas" flow.
- Add Design.icon column + migration that backfills legacy rows
(electrical -> zap, others -> dashboard)
- DesignModal: name input + curated lucide icon picker (create + edit)
- Sidebar switcher gains per-canvas edit/delete; delete guards the last
canvas and confirms
- designStore: addDesign/updateDesign/removeDesign with active reassignment
- Fix data loss on design switch: abort load when the save fails and keep
unsaved edits; skip the save-old step when the previous canvas was deleted
- designsApi create/update carry icon; design_type kept for back-compat
Tests: backend design CRUD (icon + cascade + last-canvas guard), designStore
actions, designIcons resolver, DesignModal create/edit/validation.
ha-relevant: yes
Pouzor