Fix Code-graph CI

[Naseem77]

After testing only canvas.spec.ts, tests are blocked by codebase issues:

visibility state not syncing after hide
visibility state not syncing after checkbox uncheck
isPath property not syncing after path selection
node x/y positions not updating after drag
isPath property not syncing after path selection
download button click does not trigger a file download
In short: data flows one way (app -> canvas) but never syncs back (canvas -> app).