Cmd/Ctrl+Arrow Up/Down resizes node height (±10px, ±2px with Shift).
Cmd/Ctrl+Arrow Left/Right resizes node width (±10px, ±2px with Shift).
Uses the same onNodesChange('dimensions') path that NodeResizer uses
— no new store action needed. Respects min-width/min-height matching
the NodeResizer constraints (360×200 with children, 210×110 without).
The Arrow-key move shortcut now skips when a modifier key is held,
so Cmd/Ctrl+Arrow unambiguously means resize (not move).
Updates canvas audit doc: Node Rendering section updated and
the LOW node-resize item marked done. All Remaining Gaps items
are now complete.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>