feat(132): add transition attribute to canary-modal open/close

fixes #132 /claim #132 #### Summary This PR adds a transition property to the canary-modal and canary-dialog components, enabling smooth open/close animations. Transitions can be customized using CSS variables (--canary-transition-duration and --canary-transition-timing). #### Usage Enable transitions by setting the transition attribute on the modal, and customize with CSS variables if needed: ``` <canary-modal transition></canary-modal> ```